While requiring a Google account to host a meeting makes some sense, requiring an account to join a meeting will simply mean too much friction and users will use another platform.
The equation is simple. Users use the first platform they can find where both sound and video works for every person they want to talk to. "Jim can't get into the call" soon leads to someone piping up "shall we try zoom instead?".
It's easy to see how this happened too - all Google engineers have Google accounts (for their work), so when testing this out, never encountered the issue.
I predict they'll change their stance in a few months when they see zoom still crushing them in user numbers, but by then it'll be too late - people will remember meet as that app which is "finicky to get to connect because everyone has to remember their password"