Proton Pass is an open source, end-to-end encrypted password manager app. Create and store passwords, email aliases, 2FA codes, and notes on all your devices
Proton is starting to loose focus in my opinion. I've been a costumer for 5 years only using email and I moved this year to fastmail and I couldn't be happier.
Unlimited emails alias, good apps, ability to use thunderbird without a self hosted bridge.
The promise of a encrypted email does not work if your contacts are not on proton too (for me was 100% of my contacts).
If you are really focused on privacy you would choose nextcloud for cloud for example and keypass or Bitwarden for password managers.
I would like them to focus on email client features and stop this side hustles.
Fortunately, I don't have the same experiences as you. I mean, sure, I've encountered bugs in the Android app, but I've never lost any files with my selfhosted Nextcloud server.
Setting up the Nextcloud server and optimizing it was quite a big hassle for me (took an entire afternoon), but after it was all done, I was pretty happy with it.
No, the web UI is quite slow and that probably won't change, but the caldav server and the Windows Desktop app work perfect. The automatic upload of media on my (Android) phone has no issues at all.
In my experience, the most issues are with the web UI due to its bad performance, but besides that, it works perfectly.