https://www.youtube.com/watch?v=I6tWsPSBgTc
I skipped from beginning to middle to end of this, but I wouldn't draw the same conclusion as you have. However, I think he's trying to do exactly the same thing with his voice as he was in his youth, and as singers get older it's just not possible for most of them; if they want to sing the same songs then they need to alter how they're singing it to suit their current vocal range. A lot of the time AFAIK it involves altering the key of the vocals (disclaimer: not my profession, just repeating what I remember hearing other accomplished, ageing singers say on this topic).
Listening to his voice makes me wonder whether he's constantly trying to re-live old glories rather than finding a place for himself in the current world.
It's kind of hard to do that though. Everyone expects them to sound the same. All voices change with time, especially singers. It is amazing that some of them maintain their voices quite well, but even those that sound similar still sound different. There are those who have managed over the years though (Christina Scabbia still sounds amazing 20 years later)