I think it also attracts many different kinds of players (with overlap between them). Some of the same MtG "player personality archetypes" apply to Pokemon: https://mtg.fandom.com/wiki/Player_type : hyper-competitive players, players who like swinging with the biggest baddest coolest Pokemon they can get, and combo players who like figuring out just the right combination of mechanics if you bring in some move from six games ago plus an item from three games ago plus a new Pokemon that just made the combo possible. Also throw in aspects like grinding for shinies or EVs.

Different appreciations for asethetics apply as well: people who get really into the lore, people who really enjoy specific Pokemon (look at Yellow, or the Let's Go games), people who just want "whatever has the best stats".

And each new game tends to take all of those archetypes into account when creating new content.