I'm having flashbacks to watching Nick Mason tap on the drums.
He was always very modest about his skills, but the same goes for Dave and Richard...
And I've noticed it elsewhere with old British musicians, too.
It as if they've become too refined in their old age to get dirty on stage.
Of course, somewhere after playing a song for 20+ years, you can't change it much without p!ssing everybody off, so an element of sterility and over-rehearsal comes into the picture as well.
I still love the music and lament not being old enough to see a show before they "fell apart" in the 80's.