I'm in the process of leaving Proton and moving to Fastmail. I'm now paying for Mullvad and Fastmail, but haven't had a chance to port over a bunch of Simplelogin aliases I have over to Fastmail yet (my fault for not using a custom domain for those, which I've now rectified with Fastmail).

Despite having Proton since 2018, I've really gotten fed up with their service quality — they seem to half-ass most of their services and it's a real pita to use their ecosystem. People have been complaining for ages and nothing changes, so I've decided to take my business elsewhere.

Hopefully I don't get flamed for my decision; that's another annoying aspect about Proton. There's a vocal portion of the userbase that are zealots and really take you to task when they feel you are criticizing Proton in any way.