The right for a private good exists. In the same way different countries exist, different views in copyright and the right to backup exists.
Depending on the region: yes.
I fully expect they will continue with other services so they can drive the sales of tokens.
Seconded Libro.fm
Found a (for me) working alternative for Audible.
Wether UK is in the EU or not: you people are always welcome here!
Same. Personally I liked them. After I was powerful enough to run them solo. But will look at them when they arrive (again).
Before everybody starts moving to codeberg: read the TOS. Especially regarding private repositories.
The heavy focus on FOSS can be not ideal for some people.
But despite that: works and is nice and easy to use.