[jmoss20]

It's only a problem if you want to use Bayes to take some credences + evidence and prove them irrational (indep. of prior).

Bayes is great for verifying self-consistency: given some priors and some evidence, it produces exactly one set of credences. If you've somehow got a different set, you've gone wrong somewhere (and can be Dutch-booked).

What it won't give you is a full theory of rationality--but IMO this is not a problem with Bayes in particular. No theory will. There /must/ always be some free variable that prevents landing at exactly one set of credences. All theories that disagree come with very strange (and not very believable) implications.