I often think about leaving gmail, but it's not clear what the better option out there is, that doesn't create a bunch of pain in terms of not having good replacements for the rest of the ecosystem.
Your google account still works for drive if you switch from gmail to fastmail or proton or whatever. If you associate it with a domain you control you can even move the same email address between providers.
If it's just email, then Fastmail wins hands-down, IMO. I've been a customer for 20+ years. On my primary Google account I don't even have a Gmail account at all, but a warning if you set it up like that -- some Google products do not work at all, e.g. you cannot connect Docs to Gemini without an @gmail.com address. It will give you a prompt that looks like it came from 1998 and ask you to sign up.
I keep a separate Google account with an @gmail because some web sites don't even let you sign up with non-major-provider domains these days.