For those in bands, how do you handle band management responsibilities?

For those who are in bands, how do you handle the non-performance aspects of the group? For example do you have a single person who handles everything (booking, promotion, scheduling, rehearsals, etc.)? Or do you split those duties up among different band members? Or hire a manager to do it all?

Also what kind of system do you use for managing information -- email, calendar, etc? Do you have something like a Google Workspace for the band? Or is it just one person's personal email and calendar, etc?

Asking because I am in a 5-piece cover band that's led by a husband/wife team, who have always handled everything non-performance related and operated the email and calendar out of their personal Gmail accounts. This has worked pretty well for the last couple of years because we didn't gig often, but that's changing -- which is awesome but that system is starting to develop some cracks, and we need to rethink how we divvy up responsibilities and manage information flow.