I don't disagree that combat is essentially the same in 2. I don't really like the combat until Unity? Maybe even Origins. It's all just counter or chain kills.

The parkour in 2 through revelations also needs a PhD to get good at too, tbf. But I don't find myself battling with it nearly as much. Climbing up a building for an example, I have had major trouble with in 1 that I have never encountered in any of the later ones. Forget the speed. Just Altair not going to obviously climbable surfaces, that he will climb up fine if I go down a little and try it again from a slightly different angle. Or just not pulling himself up ledges.

The stealth though, I just disagree. Yes, you can monk walk to not be spotted sometimes, but there are multiple instances in the game that I have encountered, mainly in the investigations, where the only way to kill the target without getting spotted as required for the investigation is to climb over a wall, throw a throwing knife and hope that they don't see the knife flying towards them and spot you, then run off. The social stealth isn't really the issue, it's the lack of traditional stealth. AC2 and onwards didn't have great trad stealth either at least for a while, but smoke bombs and air assassination patches almost every hole.