I have considered moving to iCloud as well. How do you find the UX? It has been a decade+ since I used the Mail app but I don’t have fond memories.
Not only that. the 2FA requirement is particularly bad. You cannot use 2FA apps (such as authenticator.cc / bitwarden / 1password); the requirement is having an apple device that you have physically signed in on before to be able to allow you to log in. Every single time. Even if you save the cookies.
I don’t need to check mail by web browser though. So maybe I’ll do it.