Wonder Trade is one of the most useful things for IV and EV training. A lot of the times in Wonder Trade, you'll get Pokemon who are used as the "breeder" meaning they don't have max IVs or at least for the stats that most trainers want to start EV training, and the original trainer has obtained the Pokemon they wanted with max IVs or at least the ones that matter (like a 31/31 IV for Charizard in Speed and SpA) so they put the "breeder" Pokemon in the Wonder Trade for whoever to pick up. That in turn gives you a chance to get a Pokemon that might have more/better IVs than the one you currently have, that way the IV breeding is much easier and less of a hassle. Plus, you know, free Pokemon that you might not have yet.

I've got a bunch of Japanese Shiny 6IV Dittos that I cloned if you want one? They're all Adamant with Imposter.