I don't think I don't see you Jane.
I'm not here but Doctor Who compels me.
I don't think Tennant's back in response to ratings, I think it's just that asking a brand new Doctor to headline the 50th is a heck of an ask. May as well bring back the most iconic modern iteration.
Era thoughts, broad strokes: I think it had promise to start with. A few good ideas, fantastic cast of guest-writers, some messiness but clearly just inexperience with running a writer's room. It had the potential to improve. Chibnall just looks like he had the wrong response and rather than learn from his mistakes and keep going with what he wanted to do, he completely pivoted to bombastic, popcorn flick entertainment that was never his strength. Flux/specials were rarely boring, but they were too packed to be anything memorable. Power of the Doctor had, like, five episodes worth of plot crammed into one, and they were good ideas, they just didn't get a chance to breathe.
Look at the newest shitfest about to come out - Indiana Jones 5. They want to do some time traveling shenanigans to kill of Indy and replace him with some chick instead 
So Disney want to squeeze money out of a franchise because they get more brand recognition and can sell more tickets and merch that way, and know Ford can't stay in the role indefinitely, so they want to replace him with a new character rather than recasting (Which, after the AI-ghouls on Star Wars, I respect) to allow for more stories in that universe. And rather than an identical character, they considered casting (for the record - they filmed multiple endings to IJ5, you're describing one of many. That took about ten seconds to fact-check) someone whose dynamics would allow for different stories as opposed to stock repeats.
You could criticize capitalism for wringing a franchise until it's begging for death, or wokeness for trying to not just do more of the same. Wonder which your priority is.
Anyway recently I watched a Doctor Who episode which vocally supported feminism and insisted pollution was a problem and that we ought to do something about it, and even one character who was willing to be violent in the name of that goal was treated sympathetically. I can't believe the show went so woke in, er, January 1974.