I've had a few of my domains pointed to G Suite since its inception. During that beta period, it was free to try out and anyone who got in then has been able to stay free all this time.
Months ago I started getting notifications that looked like they were saying it would no longer be free and that I'd have to sign up and start being billed. I didn't really want to pay for this for three domains since they're basically just toy domains, not really doing anything interesting or worthwhile.
I finally started researching my options and found this little tidbit buried in one of the G Suite legacy free edition support pages...
I used my account for personal use
...this handy little button.
For non-commercial use, you can still continue for free. You don't have access to any of the premium services, but all the core services (Gmail, Calendar, Drive, Meet, Sites, etc) remain free.
Now I'm curious as to whether a regular account, not "legacy", could use this option to declare their account is just for personal use as well. 🤔