Necrozma is pretty nutty. I predicted long ago that it'd be a sleeper threat if people started experimenting with sets beyond specs, but never could I have imagined things would come to where they are now- Suffice to say, I don't think Necrozma should stay in the tier. I won't really go too in-depth into what makes Necrozma bannable since the posts above and my aside below say more than enough on the matter.
When it comes to the best route on approaching its removal, I think the move here should be a suspect test. While people like to complain about the notion of suspecting during team tours and how they theoretically would result in people who carry their teams not being able to get reqs and lowering turnout as a result, the reality of the matter is actually quite the opposite, as we can see with the
Snorlax suspect which happened during last PL getting 40 voters, as opposed to the
Genesect suspect pre-WC getting 29, and the
Power Construct suspect getting 30. If the only other reason for not suspecting things during team tours is because people don't wanna walk and chew gum at the same time, I think it stands clear how weak the argument is. It'd be one thing if there were Ladder Tour cycles going on or if the result of the suspect would come right in the middle of playoffs, but from where we are in PL now, playoffs are pretty far removed from the situation, and there is of course not an LT going on.
As for the notion of quickbanning, I don't think it makes sense here for a number of reasons. First and foremost, the metagame just isn't in an early development phase, nor are things really still staggered from any recent major bans or changes. Second, It's not like Necrozma suddenly became problematic overnight; Week 2 of PL was a major turning point for it to be sure, though its developments were things that people were already theorycrafting and using on the downlow themselves, Week 2 simply shined a spotlight on said developments. Third, there isn't another suspect going on. Fourth, even if we did have near universal
spoken support to boot Necrozma, that spoken support doesn't necessarily always translate to how a suspect vote may turn out; a perfect example of this is the Power Construct suspect, where a notable majority of people in posts and discussion leaned towards not banning it, but then the actual suspect vote still ended in its removal; to put it simply, we cannot take any amount of spoken support for or against something as a forgone conclusion of what the people who actually get reqs would end up voting.
To sum it all up,
I believe Necrozma should be banned, and that that ban should happen via suspect test.
Also, as an aside regarding the perennial argument with each of these discussions that banning too many centralizing pokemon creates a "slippery slope" or inevitably makes the meta dumber, I think it bears understanding what the purpose of banning things even is. The point isn't simply just banning things that are too good, so much as it is banning things that are too good
relative to the rest of the metagame. I'm not just pulling this out of thin air, either; see here, from the
baseline framework for tiering policy:
III.) Broken - elements that are too good relative to the rest of the metagame such that "more skillful play" is almost always rendered irrelevant
A.) Important to note that it is a relative statement; a 200/200/200/200/200/200 BST Pokemon with standard movepool would be broken in a metagame where the average is say, 100/100/100/100/100/100, not where the average is 200/200/200/200/200/200
B.) Examples are mostly Pokemon and include strong Ubers like Kyogre, Groudon, and Arceus. These aren't necessarily completely uncompetitive because they don't take the determining factor out of the player's hands; both can use these Pokemon and both probably have a fair chance to win. They are broken because they almost dictate / require usage, and a standard team facing a standard team with one of them would be at a drastic disadvantage.
These examples limit team building skill.
C.) Examples also include ones whose only counters or checks are extraordinarily gimmicky Pokemon that would put the team at a large disadvantage elsewhere.
These examples also limit team building skill.
D.) Uncompetitive and Broken defined like this tend to be mutually exclusive in practice, but aren't necessarily entirely so.
1.) BP was deemed uncompetitive because of how drastically it removed battling skill's effects and brought the battle down to match up, but it could also be deemed broken because of the unique ways in which you had to deal with it.
2.) While this isn't always the case, an uncompetitive thing probably isn't broken, but a broken thing is more likely to be uncompetitive simply due to the unique counter / check component. For example, Mega Kangaskhan was deemed broken because it was simply too good relative to the rest of the metagame and caused the tier to centralize around it, but it could also be labeled as uncompetitive because of the severe team match up restriction it caused by punishing players if they did not pack one of the few gimmicky and obscure counters or checks for it.
With this notion in mind, we have to compare the aspects that make Necrozma good, relative to the aspects that make something like Urshifu, Tapu Fini, Celesteela, etc, good. Similarly, we also have to look back at prior bans and consider what made them so good that they needed to be banned, and then compare those aspects to where Necrozma is now. When you take a good long look at Necrozma, its strengths are pretty clear to see: Absurd offensive power both in stats and moveset, insane versatility in viable item options, moveset, and stat spreads that allows it to run near anything it wants and still do well, and a lack of meta-relevant threats that can consistently handle it or even blanket check it without otherwise bending over backwards in a way that severely limits teambuilding skill as described above. If we compare these factors to any of the other top mons in the meta right now, we can immediately see that nothing really encapsulates all three of these aspects quite as well, compared to Necrozma; While there are certainly similarly strong, if not even stronger, threats than Necrozma (Regidrago, Porygon-Z, Darmanitan-G, etc), they end up lacking either versatility or are more easily covered, and while there are certainly similarly versatile threats (Zeraora, Celesteela, Dragapult, etc), they just aren't as strong or are still easily blanket covered, and while there are threats that are similarly lacking in weaknesses (Primarina, Spectrier, Cresselia, etc), they still struggle with power or are lacking in versatility relative to Necrozma. To put it simply,
Necrozma is far and above the best Pokemon in the metagame right now. When there's this much of a disparity between the best options and everything else, that is when we have to start looking into a potential removal. The ideal metagame we strive to build towards should be one where the top of the game isn't so far removed from the rest of its competition.