I know it is a little silly and they probably do what is (in the short term) the best financial decision for them, but I already accepted that this is it and I won't listen to them anymore.
If you go exclusive to any plattform you never do it for your fans, but essentially against them. They might have a podcatcher they listen to you on they used for years, which they now should change because you want to limit the plattforms you are on.
The german podcast scene gladly seems to be quite resistant against these kind of things and they say they earn more through direct donations than spotify and/or audible is able to give them anyways.
Why would you voluntarily give up that freedom? And why is it so often US podcasters who do it first (they are also much more plastered with ads)?