Why is it important to catch a pokemon as early as possible?

Question

Becuase im to lazy to train a meinfoo.

Answer 1

It's not always important to catch a Pokemon as early as possible. If you're too lazy to train a Mienfoo, go catch a Mienshao at Route 14.

But training helps your Pokemon. EV training is very important, and an EV trained Pokemon at level 50 is better than a wild un-EV trained Pokemon at level 50.

Hope This Helped :D