I've cancelled my subscription yesterday, conveniently it was about to renew at the end of the week, so I have a few days to migrate from Proton, here's what I'm thinking of, but I'd love to hear what other people are switching to
I went with mailbox.org's 1 dollar a month plan combined with addy.io, which also had a 1 dollar a month plan and that lets you have infinite aliases.
This combo has served me well. But it has a fairly limited storage space for email on mailbox and bandwidth on addy.io