>>713644484 (OP)It kinda happens already with some TCGs that have 9001 cards but "the meta" uses like 300.
The main problem I see is that your game would only have one meta forever, essentially being a solved game. Everyone would just use the single best deck possible made from that 300 card pool and that's it, it turns into a purely RNG-fueled game where whoever gets the win condition out first wins.
In other TCGs, by adding cards regularly they make sure the meta changes and the game survives (and also they can sell a crapton of shitty cards for massive profit), this obviously comes with a lot of disadvantages for the players like power creep, unusable bulk, formats, etc. but as long as the money keeps coming that's fine for the companies. There's also the huge gambling factor.