In the beginning of Dark Souls, you can kill every enemy pretty much the same way. Then gradually you need to use more mechanics to get forward. Very little of it is actually mechanically demanding. What's demanded of you is that you observe and correctly assess the situation, that you recognize that what you are doing isn't working, and the solution isn't to do it harder, but to find another solution.
The biggest problem most new players have is that they try to play too fast and they don't react to what's in front of them. They mash buttons and try to do everything at once. They approach every situation the same way, probably rushing in and probably pressing every button on the controller in a mindless flurry. An seasoned player will almost certainly play slower than a newbie because they're playing a lot more deliberately.
You have people playing these games with voice commands[1] and DDR mats[2] and whatever. If that isn't evidence this isn't a test of dexterity, I don't know what will.
[1] https://www.youtube.com/watch?v=5m2a2dLdZ0M [2] https://www.youtube.com/watch?v=UxKsRf6R-vc