It always seems to me that any notable Pokemon challenge run idea tends to lead to grinding if you want to win. Mono-typing, no evo, Nuzlocke, etc. (no Pokemon Center runs being a big exception unless you're willing to wait for berries to grow), which I don't think makes the game more challenging as more tedious (and time-consuming), and if I want that, I'd play Dragon Quest. It just seems counter-productive, especially for Nuzlocke. "I want to increase the challenge, but I don't want to get screwed by RNG, so I'll spend more time than I would without the self-imposed rules to get to a point where I won't messed by luck, but now there's no challenge because I'm overleveled." People have fun in their own way, but I personally see grinding as a game design flaw.
@.access:
I hope SwSh has a great replayability because I've been saving all my alternatives playthroughs (nuzlockes, funrun, monotypes, etc.) for the day a pokémon game would allow multiple save files
We might have had that in the first game, but… the Game Freak's staff unanimously voted that it was better if the player could give their Pokemon nicknames.