It really is life changing. When you have your own domain switching email services is risk free since your addresses don't change. You can literally try out all the email services out there.
For the record I'm a happy Proton customer. They seem to be the only ones who still care about PGP. I even interacted with them here on HN a few times.
I just moved away from Fastmail after 10+ years for this reason.
any avoidable dependency on the US has become a red line
don't forget to tell fastmail that the reason you're leaving is because they host in the US!
(I also told them if they open a DC outside the reach of the US regime: I be happy to become a customer again)
I am using them.
Sending an email from catch-all covered email is not a big issues also, create use, delete and it still works.
I am slowly transitioning to icloud from gmail, was thinking of proton but reading the above comment made me change my mind, good custom domain support is a must for me.
I have a catch-all and can reply from any address I please. If I reply from an email sent to retailer@mydomain.com it even auto populates the "from" address for me with "retailer", or I can choose to reply from one of my named accounts. It's really slick.