The only “real” competition for Google Workspace is Microsoft if you need a full collaboration solution beyond just email, and 99.999% of customers of such hosted solutions need that full solution. It’s why Dropbox worked even though hacker news users probably roll their own sync solution.
Proton has calendars, drive and meet.
And is not a US business, which is an important selling point to several companies and public institutions here in Europe.
Tuta, Fastmail, and Posteo are all much better alternatives to Gmail in terms of privacy.
My comment, as per subject, is about Gmail.