Unfortunately what you are most comfortable could also cause repetitive stress injury like carpal tunnel. I have a brother in law who damaged his nerves because a Macplus keyboard felt best to him.
I've been using a computer on an almost daily basis for over a decade now, and before that I used one whenever I had the opportunity because I've loved computers since I was a kid. I'm 30 and have carpal tunnel in my mouse hand, not bad enough to get it surgically fixed, but I wear a wrist brace pretty much 24/7 at this point to keep the pain under control.
That said I agree with your point about using whatever you're comfortable with completely, just wanted to throw my own anecdotal experience out there for others to see. Everyone's different and what's fine for you or me may not be for others.
That sometimes works, but sometimes the right way is not immediately comfortable so people so stuff that seems right and hurt themselves. Sometimes the thing that seemed correct initially was only because of a lack of deeper understanding and an ignorance of the knowledge of those who have already made the mistakes.
I dance, play instruments, drive cars, and do a whole lot of other things where the immediately comfortable thing is so often one of the best ways to develop a massively limiting habit that is a huge pain to get away from once you realize how badly it’s holding you back.
It’s a case-by-case basis, of course, but simply “the best is what you’re most comfortable with” does not have near the nuance it needs to not be abused. It is great advice for people once they have built up a strong base of knowledge, and until then they need to get over it and try things.