What if in a new gen, to match up with some of the anime bullshit like Ash not evolving his Pokémon yet them still being viable somehow, they introduce a new gimmick that let's you lock a Pokémon in it's current form, but gives you the stats of it's final evo?
You'd probably have to lose the ability to use Eviolite on the Pokémon you do this to, but it'd let more people use the forms they favor