The rule that prevents every hostage situation.
One sentence of policy saves businesses from the most common mess I see.
You are always the primary owner
Your business's profile should be owned by YOUR Google account, not your agency's, not your web guy's, not an employee's personal Gmail. Helpers get Manager access. Always.
Managers can do almost everything
A Manager can edit info, reply to reviews, add photos, run the day-to-day. The only things they can't do are delete the profile or control who owns it, which is exactly the point.
Agencies come and go; the profile doesn't
When you leave a provider, you should be removing THEIR access, not begging for yours. If a provider insists on primary ownership, that's not a workflow. That's a leash.
Buying a business? The profile is an asset
Years of reviews are part of what you paid for. Put the profile transfer in the closing checklist alongside the keys and the bank accounts. It's worth more than the sign out front.