The stuff you're taking about is like big AAA titles, and for all the passion people have for the console it's really not about that kind of stuff because porting it isn't necessarily easy or possible because it's so (relatively) underpowered. Obviously some Devs have made the effort with older stuff (e.g. Witcher 3, older Assassin's Creed things) but generally unless you embrace Nintendo first party titles and indie stuff I suspect you'll be frustrated.
Good points all, but playing Devil's advocate for a moment, is the Switch underpowered compared to the PS3, the initial home of GTAV?
Being even more DA-y, I don't think GTA is an RPG. But with Skyrim on there, OP should be content? At least before discovering the beauty of the JRPG.