As someone who's put 60 + hours into both, I've give the slight edge to Xenoblade 2 if only because of the price of Skyrim Switch.
In a vacuum I guess I'd slightly favor Skyrim as I prefer more of the WPRG/open world types, but Xenobalde 2 is definitely $60 well spent, and it's not often I can say that when it comes to games. You can't really go wrong with either.
Basically, if you prefer a more open world WRPG that leans more heavily on gameplay, go Skyrim (although that's not to say Xenoblade 2 isn't a deep and complex RPG, far from it).
If you prefer more of a semi-linear, story driven JRPG, go with Xenoblade.
No need to beat around the bush. XC2 is extremely linear. Not a problem at all when the world is so vast and linearity is innate to the genre.
Well, this is new.