IIRC, PBS already has their own “Passport” streaming option. This is just a play to expand their potential audience. But if you don’t want to deal with Amazon, you’re free to deal with PBS directly.
Per their FAQ[0], this doesn't apply to every member station. It's also notably cheaper than other streaming options ($5/mo or $60/yr minimum donation) for ad-free content.
If this one makes it clear what is and isn't available if I pay for the service, isn't full of useless "clips" crowding out real content, and lets me filter out stuff that's just Youtube videos, I'll take it over Passport (assuming the "what is available" suffices).
Then again the Amazon Prime app has similar problems so probably it won't be any better.
[0]: https://help.pbs.org/support/solutions/articles/5000692392-w...