Logan is about twenty minutes too long, has lots of very silly moments, and has its head way up its own arse in the way a lot of westerns do. But apart from a few bum notes at the very end, it's vastly superior to most superhero films.
It achieves its superiority by doing some simple things the vast majority of superhero films don't in a workmanlike way: convincingly depicting moments of human frailty, vulnerability and intimacy, and drawing on cinema history for inspiration.
How easy it would be for all franchise cinema to suck as little as Logan did—not necessarily to be great, but just to be not awful.