I have totally replaced Drive/Docs/Sheets with Nextcloud [1] + OnlyOffice [2]. You still get online cloud storage and online editors with the bonus of using the widely popular (OOXML standard).
2. https://www.onlyoffice.com/
As far as Gmail goes, I have heard really good things about Fastmail (as others have mentioned) or if you want to host your own, I highly recommend checking out mailu.io.