>Fact: if a Pokemon is distributed widely within a generation, it counts as catchable within that generation. Because this is intentionally done to make that Pokemon available.
>Fact: unless you catch them all exclusively within a generation with your own games trading with yourself only, you're a casual.

With these two facts that in mind, gen 7 is literally the first generation where you can't catch them all. It instead forces you to be a literal casual transfercuck who thinks because he caught Nidoran in generation 3 he deserves to have it permanently in every other game.