This is a super opinionated question because everyone has different priorities. I do think most folks who care at all about "glass" usually end up owning more than one set of bino's. I have a pair of 10x42's and a pair of 15x56's.
I personally believe glass quality is more important the higher you go in zoom range. My 10x42's are pretty low-end but it doesn't really affect their use at all. Sure, compared to my friend's Swaro's, I can tell the difference - if I use them both side by side for a few minutes. But out in the field, just with mine? They're 100% fine. But in the 15's, I definitely notice the difference, and honestly I think anything about 12x is pretty unusable if it's not high-quality, regardless of the maker.
I carry the highest zoom whose weight I feel like dealing with for the day. That means I usually have my 15's for most trips, and I grab the 10's if I want something lighter for an afternoon hike or something like that.
YMMV