Many password managers these days support passkeys and can synchronize them in whatever way you use to also sync your passwords (i.e. a cloud backend, but also a self-hosted Syncthing shared folder etc.)
I can easily export and import my passwords from my password managers and do whatever I want with them. I enjoy having that lever over my subscription.
There are several subscription-free password managers available that support passkeys, e.g. Bitwarden (self-hosted), Strongbox (lifetime version available), or KeepassXC.
It's unfortunately not quite the same level of portability as passwords, as I don't think there's any standardized export/import format yet, but these options are significantly better than Apples's and Google's closed ecosystems.
