The problem here is there's no way out now. If 15 years ago you made the mistake of wanting gasp a domain for your email, you're basically roped into paying now.
Almost everything a free G Suite user wants is identical to the free @gmail account, which is remaining free. Except the custom domain. Fine - but there's no way to just lose the custom domain at this point.
Over the years, the Google account has grown in importance and things tied to it. It's fairly un-viable to migrate it to an @gmail account. Especially for your whole family.
So, the options are nuke all your Google accounts and suffer the consequences, or pay up.
Not like we didn't see this coming of course, but still sucks.