Well, in general - would you use your personal email account for work?
So for example - say I have a personal Gmail account (e.g. cute-boy-88@gmail.com)
But if I was working for a company that had spun up GCP infrastructure - my work would likely provide me with a work email address (e.g. trevor.jacobs@bankofengland.co.uk) - which I would use, rather than cute-boy-88@gmail.com.
This also covers the use-case that for example, you leave the company (in which case the company still controls those accounts), or an employee goes rogue and tries to takeover their work account.
In general, you would try to keep your work/personal accounts separate - you're not going to put your personal account as the recovery email for your work account for example. Your system administrator (or IT team at work) is going to be the one who resets your password, or recovers your account - and they're not going to send private work passwords to a personal email account (or they shouldn't).
Hopefully the above helps.