Every time one of these threads come up I like to share my experience attempting to use protonmail for my business:
Protonmail charged us for every email account, whether or not they were active. When an employee left the company, we would disable their email address but we wanted to keep records of their email history. Of course, exporting email from protonmail is difficult to the point where you need an engineer to do it.
So I emailed protonmail saying "hey, do you think you could add a feature where email addresses can, say, be permanently disabled and then we don't pay for them any more?" They replied with a typical protonmail brush-off.
I was already frustrated with the service because their search is worse than a simple substring search and after a few years of using an email provider for professional use you sometimes have to find old conversations. So I canceled the account and closed the privacy.com card.
A year later I noticed that the (luckily closed) card was still being charged monthly, so I tried to log into the old account to see if there was a problem and the password (stored in a password manager) didn't work. I emailed them to let them know there was likely a bug and their support agent argued back and forth with me about it before finally demanding my credit card information (which I didn't have, the card was closed a year ago) to stop billing me. I just stopped responding at that point.
In my mind the fact that they are so hostile to their users is a big red flag. I think it's bad practice to trust people who indignantly dismiss reasonable questions from paying customers with private information.