Oldschool. Things like this I am doing for many many years, and I will continue for many many
Trees made me sometimes miss school because climbing them was more important. Actually, I would propose to every 16-20 year old that comes fresh from school to come to us for some time and learn all the things that school didn't teach or actually destroyed.
Btw. if the enjoyment of touching trees and moving through them is not enough for you: This is organic strength training par excellence. There are some basic situations here, but the variations are endless, similar to wrestling with someone. The strength created with man-made tools is not directly transferring to this scenario, the first time you try to climb through these trees you will fail. The whole body coordination needed here is not developed properly on the pull-up bar or gymnastic rings.
⠀ You don't need to cut the tree down and make a tool to practice with it.