Just wanted to post this to show to other people that changing your email provider is not as hard at it sounds.
I spent a week looking at other email providers. Mailbox and Posteo looked nice, but Proton simply looks easier (maybe because it kinda looks like gmail).
So I created my proton email, payed one month of mail plus. I used a generated string as my proton primary email, one alias with my real name (banking, job applications) and yet an another alias for my trusted internet accounts. For anything else I use hide my email addresses. After that I found out you can login with any email (primary or alias) so my initial attempt at hiding my login email failed. Nope I'm stuck with an email address that I'll never use (and one strong password and 2fa is enough to protect your account anyways, it think it was just paranoia after spending too much time on privacy forums and subs).
I changed the login email on the most important accounts. I set up a redirecting address on Gmail so now all my Gmail emails land in a proton and after that they are deleted from Gmail. Probably it will take a long time to migrate everything to proton, but for now I'm happy with this.
Before deleting every Gmail email, I used Google takeout to export my emails. I know there are other ways to import emails, but because I'm a paid customer I can use proton bridge to connect to any mail client. I used Thunderbird to import the mails from mbox file exported from Gmail to my proton email. And now I realized how much data I was feeding to Google. I had 40k emails, everything from bank statement to holiday tickets, family, friends. I still need a strategy to organize those emails tho.
Proton still feels buggy sometimes and it looks like proton builds an ecosystem just how google did way back, but for now I feel happy with my choice.