Your 4th point really hits on the main problem with all lists like this and that is that what is “best” is different for everyone. I agree with you that this puts too much weight on storytelling, but I know for some people story is by far the most important part of any game. For me, I rarely care about the story at all, I just want interesting mechanics.
Historical Legacy is a good way to put it. For Pokemon in particular, RBY was the franchise for a lot of people, myself included. I’ve played a few of the others, but RBY is what came out when I was a kid and will always be the one I remember.