Janet Fielding (more added as possible):
I think the Capaldi era was largely excellent and still underrated, but I do think by the end it was time for a change from Moffat (just not Chibnall). I also liked Bill a lot, but I don't think they needed to do another improbably happy ending for a companion where a death is inverted just like Clara's.
I will agree the Chibnall companions are total ciphers. It is not a coincidence that the only actors that have managed to break out a little in the current era are established performers with their own preexisting name brands - Bradley Walsh and John Bishop.