You're going to get a lot of different perspective here because there are a lot of different methods, techniques and perspectives. Most guys will learn a certain way, they get comfortable and with that and the rest of their career is spent climbing with that method, or various variations of that.
Very few of us are trying every method and technique and hitch and device to find an ultimate system. Those guys are the innovators, though the black sheep in the industry, outside the norm.
You're likely to get information from the norm and become the norm. Nothing at all wrong with that. The tree climbing industry has essentially been climbing trees the same way for over a hundred years. Some things have changed, like manila and hemp to nylon and high molecular weight polyethylene. Saddles have gotten better, more guys use caribiners and slings and there's the BigShot, but climbing technique is still rooted and practiced in the use of the friction hitch. A lot of modifications on it, but a time-tested way of working trees.
Friction hitches are unique to the tree climbing industry. Yes, there are prussiks used all over in other aerial disciplines, but climbing on half inch line using a friction hitch is uniquely us.