Ive thought a lot about this. My business is trapped in the google suite at the moment. I think the easiest transtion combo would be proton, which covers emails, calendar, drive...and for ease of use compromise telegram for chat / calls / screen share. Thats where im gonna push my business. Id say simplex for calls and messaging but gotta think abt employee transition.
Discussion
With proper education & training during the swap I don’t think you’d have a problem.
Change is always uncomfortable especially when it’s significant.
But that suite should give you more control over your businesses data & privacy/security upgrades for your employees and you.
You could self host an ftp server & setup remote access to those who need it.
Good luck