If you want to do it as fast as possible, check out the various speedrun routes for the game. I'd link them but I still have new account restrictions.
That said, anything will work and you could just smash your way through the game with your starter easily enough. Check out the Smogon Ubers...
I wouldn't be surprised, especially since I'm assuming the Switch's successor will be more of a Switch 2 than something completely new. ...but god, I hope not.
You're going to have a hard time finding ones targeting modern platforms that don't use analogue triggers since they've been the norm for a while now for everyone except Nintendo who weirdly only did it for one generation and are necessary for entire genres of games (namely racing games). There...