Yeah, if you add too much more to the possible moves each Pokemon can pick, levelling up starts to become a chore because you have to re-evaluate your move choices so frequently (less of an issue in more deliberate training, but if you're just casually working your way through the story and aren't already sure what you'll pick, every new move opportunity is a decision to consider, which gets really tedious if it happens too often).
At least with S/V they included an NPC trade for a Haunter, but didn't give that Haunter an Everstone like previous generations did, so it evolves into a Gengar as soon as you get it. Trade evolutions are indeed a pain, though. As much as I recognize that they're just trying to provide an incentive to play with friends, it actively hurts the game for people that don't have friends playing it.
Unfortunately they didn't do that for Scizor. By the time I finished the Pokedex the "new game feel" already wore off.
Maybe I'll get into the shiny hunting whenever the DLC comes out.