Question, how come there isn’t a national dex random battles?
A National Dex random battles format doesn’t exist for several reasons:
1) Lack of Demand — NatDex rands is a semi-common suggestion we receive, about as commonly as LC rands (perhaps slightly more). We do not know how this would translate to player numbers, and we already make a lot of formats. It’s conceivable that NatDex rands wouldn’t hit the activity quota to stay, mainly because…
2) The Format Would Probably Suck — The worst part of rands which everyone hates is a bad matchup, especially when your team is actually quite good, but your opponent just has that one Pokémon with the perfect attributes to roll over your team. When you have every Pokémon and mechanic in the game, including discontinued ones, the chances of this happening actually increase significantly. Part of the reason for this is movesets cannot be optimised, because there are so many Pokémon each Pokémon might go up against. Pokémon with Fire- and Fighting-Type coverage whose STABs are resisted by Steel-Type would probably have to run both of them in NatDex, for example, whereas in something like Gen 9 there is usually an identifiable optimal one we can glean by looking at the specific Steel-Type Pokémon in the format.
3) It Would Be Stupidly Hard To Make, Or Oversimplified — Our other formats have a limit of 10 roles. 1 of these is used on the generational gimmick (Tera, Z-Moves) and in NatDex that becomes 2. This would mean losing another role, further meaning some Pokémon would have bad item generation rules just to accommodate both gimmicks. On top of that, a format that needs to check for 3 rejections between those 2 gimmicks and Megas would result in some pretty complicated coding. This isn’t to mention the amount of work that would go into designing and modifying sets, which again we’re talking about every Pokémon in any game here, and many Pokémon would be left in “works on paper” mode in relative perpetuity because designers wouldn’t get the requisite playtesting with them, because appearance rates for each individual mon will be low.
By the way, NatDex rands has never actually been a “no”. It’s mainly been a “if we can find a way to make it work and somewhat fun and randomly have time to full send into that” and those conditions are unlikely to ever be met to be honest. We’re doing full old gen revamps still, DLC2 is on the horizon, we have another revamp on the way, potentially an additional current gen rands format that isn’t NatDex next on the agenda (no promises on that though) mixed in with running tournament circuits and all sorts of other stuff. Towards the end of Gen 9 we have factory formats to make too and they take priority too. Honestly I’d foresee this being more feasible in Gen 10 because we wont be doing full oldgen revamps during it lol.