*It's a shame that the free/cheap password managers that regular people would us...

It's a shame that the free/cheap password managers that regular people would use (like those by Apple, Google) seem unwilling to loosen their platform lock-in

How do you mean? You can export your passwords from the Apple app:

https://support.apple.com/guide/iphone/export-passwords-iphf...

Does Apple have an Android or Windows app? Well, no, and if that's your meaning then I can see your point.