A list of logins available in the browser. Here's the support page for it: https://support.google.com/accounts/answer/1721977?co=GENIE....
Lots of screenshots around if you google "Google Account Chooser".
Pretty much everyone who works for a company that uses GSuite will be very familiar with it.
These urls are blocked for me, but, from what you've said, it's about maintenance in paid gsuite, which doesn't mean more than one account per user.
Google gives free storage, etc per account. I wonder, if you exceeded that and had a second, how quickly they'd say 'one account per person'?
That doesn't mean more than one account per person is OK though. Just the reality than more than one person may share a device.