It's been so long since I've watched Doctor Who. I started with David Tennant and stopped watching maybe halfway through Peter Capaldi's whack at it. I know there's a couple new seasons of a woman Doctor and I heard the newest Doctor might be black or Indian but I could be wrong on that. David Tennant's probably my favorite but I definitely grew to like Matt Smith as well.
I agree that it does feel like Christian Bale did Love & Thunder for the money. His presence was also probably a plus for the film's marketing overall since he's a pretty popular name. I'm not familiar with all of Taika Waititi's work but I liked his vampire comedy movie and tv show, really liked Ragnarok, and maybe perhaps Love & Thunder exists just to prove that everybody makes mistakes. I agree with you that if the economy keeps at it we're going to be seeing a lot of old faces returning to the silver screen to stay financially afloat in these rough times.
These actors aren't doing movies like Thor 4 because they pay well. They're doing those movies because they have bills to pay. Child Support and 3rd mortgages and 5 ex-wives don't pay for themselves!