I'll get to it eventually. It's a large game, isn't it? I can only complete so many mega-adventures at a time!
It's about 60 hours if you only do a little side-questing, could probably be done in 50 if you just made a b-line through the main quest but you would miss a ton of stuff. There is so much to do in the game though that you could easily put in 100-200 hours finishing all the side quests, obtaining all the rare blades, maxing out the rare blades, treasure hunting, etc.
The game is amazing, easily my favorite Switch title personally, and probably in my personal top 5 games of all time.