Trade evolutions are the ultimate cuck move. Imagine catching and raising a pokemon, like it's your own family member, knowing that you have to trade it away someday. You have to do so as a trainer, because otherwise it won't reach it's final stage and it''s full potential. You're actively holding it back from achieving what it always wanted to be, the very best. But once you do, it's the other trainer's pokemon now. That trainer gets to reap the benefits of a powerful, fully evolved pokemon and soon, their bond will wipe away what you once had from it's memory. You'll never see it, again. You are just a portion of that pokemon's journey, not it's destination.