I fully switched to fairphone 5 but with proton paid accounts last year.(that was before the hoo hah of their CEO tweets making the rounds). At that time Murena did not support custom domains and I needed that.
Now the E/is and murenas web apps (running with nextcloud, you can get their cloud instead of nextcloud self host, and use a local drove for backups, (that is what I do).
That can work really well. Look at their compatible phone list. I flahsed on am old Sony I had and ran parallel with fair phone on Google android and got comfortable moving things. Then flashed eos on fp5 and formatted Sony. Now another family member will repeat the process.
And for calls and things I am using jitsi and signal.
Check ZSA website for ergo or checkout Nuphy website for traditional mechanical slim ones. Or checkout WASD keyboards for custom.