I'm a well-used 40 year old (still a young buck in some circles) and from everything I've seen, 1-sticking is the hardest to do for someone with a bad back, arthritis, etc.
Sticks are the easiest but height is limited. This can be extended with aiders but can be a PITA descending, especially in the dark. SRT is probably the second most fluid but requires staging trees with paracord or a fair amount of messing around with the right tree to get the rigging set before climbing. For me, 2TC is the easiest and most comfortable to get decent heights (tree dependent).
With my back, knees and shoulder, inch-worming up a tree is smooth and straight forward with less "stuff" than even sticks. Essentially, I just stand up and sit down. SRT would be even better but like I said, it requires more pre-planning.
I also realize that as I write this, there's 60+ year old's out there with less wear and tear than me