I recently migrated my email hosting away from proton. I paid for unlimited for almost a year, but I just couldn't take the missing features anymore. Maybe some of the missing features can be justified by security reasons, but some is just laughable.
If you want to use a proper email client, you need to host proton bridge in your local computer. You can only host imap and SMTP on localhost. Headless is not really supported, so good luck if you want your server to email you logs. Use VMs or docker containers? Fuck you.
On android, the only option is using their crappy mail client. For example, this client has not functionality to select all Mail from a folder if you want to archive it or mark as read. You have to select every single Mail one at a time.
Proton drive can only be used over the Webinterface or with some windows (gui) client. No automating your backups to be pushed there.
I switched to mailbox.org, which has weird 2fa but besides that makes my happy by just working with the damn standards. Not like email transfer is unencrypted when using STARTLS. Security is important, but for me personally, usuability has to be at least good enough.