I'd like to voice my opinion of Dynamax and why I would vote BAN on this mechanic here and in the future (I may try to go for reqs later), and I'll dissect all points for and against.
Dynamax is clearly the most controversial mechanic ever introduced in Pokemon. First, we had Mega Evolutions, which while they balanced weaker Pokemon, also broke stronger individual Pokemon and created what I call the "UUBL" problem in Gen 6 and 7, in which countless mons build up in UUBL due to being broken in lower tiers. Next, we had Z-Moves, which created a 1-time nuke move, some of which made unviable moves on Pokemon viable. It too had similar effects as Megas on the meta, but was generic: it made all Pokemon slightly better rather than a select few. I'm going to skip Let's Go's Candy mechanic for now, but I will discuss it later.
Now, we have Dynamax, which is Game Freak's latest gimmick that attempts to combine aspects of both Megas and Z-moves into 1 mechanic. I'm not going to go over the specifics of details, but I'll go over points for and against, and counter those anti-arguments.
1) Dynamax is Broken Because of The Auto-Secondary Effects. This is the main problem with Dynamax and why it is superior to Z-moves. While we saw a small snippet of these kinds of secondary effects with specialized Z moves such as Kommonium-Z or Mewnium-Z, which created secondary effects, and the amount of sheer usability they gave to individual Pokemon. Now picture that kind of brute power but on every Pokemon. People tend to focus only on Max Airstream for being the true broken factor, but I say that it's MANY of the Dmax and even some of the Gmax moves and their effects that can change the entire course of a game. While Fighting and Poison types have a BP reduction, the fact they can set up offensive sets for during and after Dynamax is nearly as broken. Fire, Water, Ice, and Rock can set up weather which either effectively doubles the power of STAB moves, provides chip damage, or even provide doubling boosts for their respective abilities, meaning they don't even need Weather setters for themselves. Of course, Max Airstream is the most busted of all, providing a Speed Boost, letting Pokemon like Gyarados, Hawlucha, Corviknight, Togekiss dominate OU. It should be mentioned that only special Z moves in the past had these kinds of effects; Now, every Pokemon has access to these kinds of special Z moves.
2) Dynamax Disrupts Offense by Doubling HP. Interestingly, this isn't talked about as much as it should be. But the literal doubling of HP temporarily lets every Pokemon experience a free Power Construct for 3 turns, meaning moves that normally could kill will fail to. I've seen people use their Dmax on mons like Toxapex to prevent opponents from KOing it, and using the move to scout out and waste the opponents Dmax. While Pokemon with Z moves have a huge power boost, they retain the same HP as regular, meaning they keep the same chance as usual to fire off a 1 time, Dynamax gives every Pokemon usually 1 or more opportunities to fire off Z-move-like nukes, which as described above, are more broken than most regular Z moves.
3) Three Turns is Far Too Long. Three turns allows Dynamax to boost at least once, regardless of Max Guard. In most situations, players don't Dynamax at the same time, meaning only one of the three turns can be blocked by Max Guard. Regular Protect doesn't work either, because while it stops MOST of the damage, it allows the secondary effects to occur. Even predicting Dmax moves to inflict as little damage as possible still means that abusers can set up weather, terrain, and stats for sweeping down the road.
4) Dynamax is Already showing Centralizing effects. I just need to mention that Ditto has top 10 usage. Ditto has never made usage in ANY competitive tier, especially OU. Many people often say that "Ditto is only as good as the rest of the tier" and its usage is showing that this tier...is VERY strong. Togekiss also has made OU simply because it can abuse the Dmax mechanic.
Now, from what I've seen, there are several points against banning Dynamax, mainly these: 1) There is no precedent for banning an entire generation mechanic 2) Dmax is fine right now 3) Why not ban broken mons instead? 4) Only Dynamax is Broken, not Gigantiamax. 5) Dynamax checks Dynamax. Now watch as I rip these to the ground.
1) There IS a Precedent for Banning a Mechanic: Ah time for the hatred to rain in. While you were all still playing with Lando-T and Magearna in 2018, I was off to try out Pokemon Let's Go's metagame. I was a staunch defender of the Candy mechanic, and I strongly believed that it was integral to what made Pokemon Let's Go special compared to gen 7. However, not only was it quickbanned, but I soon realized that it was a good ban. Keeping Candies would have meant a stall-like, centralized hell of a metagame where nothing dies and Eevee dominates all battles. Banning this mechanic meant that Let's Go could show us some limited growth that it would have not seen otherwise, such as the emergence of Dugtrio-A, Poliwrath, and Charizard-X as viable possibilities. Is LGPE the most centralized game in history? Yes. Is it a poor example? Yes. But it's a metagame that became better after its defining gimmick was banned.
Also Dmax is currently being banned in OM's right now. There's your precedence.
2) Dynamax May be Fine Now....But What About the Future? People tend to only look at the "now" when determining whether something is broken, rather than looking about both now AND the future. When Pokemon Home launches, Pokemon such as Blastoise (Shell Smash), an improved Mew, Celebi, Jirachi, Coballion, Virizion, Terrakion, Keldeo, Kyurem, Decidueye, Primarina, Necrozma, Zeraora, and Melmetal all have OU potential. Some of these mons will be banned because of their raw strength (Terak, Keldeo, Coball, Zeraora), but others will become tedious and centralizing with a Dmax Mechanic. Mew will be able to set up....anything, using its near endless movepool from Home. Jirachi will be able to set up Defense using Max Steel. Virizion can set up Speed and Attack with Bounce and Close Combat (same with the others). Decidueye can finally make use of Brave Bird, boosting its speed and becoming a massive threat. Necrozma can boost with Dragon Dance and power up with Dmax Mindstorms secondary effect, creating Psychic Terrain. Melmetal can abuse both Dmax and Gmax with decent coverage options.
My point is, this problem will only get worse. If Game Freak decides to move this mechanic to future games, this problem will continue. See my next point.
3) Banning Individual Mons that Abuse Dynamax Does NOT fix the Problem. There's 2 problems with the "just ban Pokemon instead" argument. First, banning mons that abuse Dmax now only opens the door for underused abusers such as Charizard, Crawdaunt, Mew, Kommo-o, and others to enter the tier and continue making things somewhat of a hassle. Something will ALWAYS be the best Dmax abuser. Secondly, banning OU mons does not fix the issues of lower tiers and Dynamax, which I assume will quickban Dynamax on their own, or when this succeeds.
4) Any G-Max Pokemon with D-Max Moves Can Still Abuse Them. Do I really need to talk about this? It's pretty obvious the entire mechanic has to go, despite GMax being slightly inferior. Moving on...
5) Dynamax does NOT check Dynamax. Ask yourself...would Primal Groudon in Gen 7 OU check other Primal Groudon? Of course not...Primal Groudon breaks everything else. Similar logic can be applied here, just not as extreme. A broken Pokemon can NOT be a check for itself; such a check inherently only adds to its brokenness and should not be applied in ANY suspect test.
There are cases in OU currently where certain Dmax Pokemon cannot check others. Ditto has risen to prominence because it is the closest thing to a check. But not only will opposing Ditto fail to check the first Ditto, even Ditto has a copy it cannot beat. Hawlucha gains its Unburden boost through losing an item, something that would be an extraordinarily strange and rare circumstance, especially after copying an opposing Hawlucha.
These are my thoughts. It's a lot. One last thing for everyone, it's important to mention that this issue should have NOTHING to do with Game Freak's Dexit policy or the quality of Sw/Sh.
Happy reqs everyone