I got my first dangler about fifty years ago with a scandi fishing knife, and a few more since then, again with European made knives, so the dangler is not a new concept, it's just more new to us here in the last few years.
As a sheath and holster maker most of the sheaths that I've made lately have been danglers by request, more than a few have been returned to be converted to belt loops, I could be wrong but I think the the fascination with dangler sheaths is more a fad than from any form of better way to carry a fixed blade knife.
I've been around a long time, so has bushcrafting, but the name is fairly recent, before that it was called Woodcraft, and the knife of choice was usually a common hunting knife and we all got along fine with them, then something "new" came along, Bushcraft, with it came new (to us) ideas about gear mostly and a few new skills, with it also came the "Woodlore" styled knife and dangler styled sheath.
While not condeming either, I am suggesting that bushcrafting can be done just as well with a plain old fashioned hunting knife and a belt looped sheath, my personal preference is I don't like anything that bounces around on any part of my body, including my legs, and I've never had a problem with a conventional leather sheath being in my way while sitting, as a police officer I spent many years sitting just abaout anywhere a person could sit while wearing a whole belt full of tools of the trade without needing to have them dangle.
Again, if it works for you by all means use them, but for myself, a belt loop is just fine, and the only "pants" a decent knife should wear is leather, no offense, but plastic is cold, has no character, is noisy, and will wear the edge on a knife a lot more than leather.