Sadly most people (at least in my country) use Facebook for this.
Instead, their messaging strongly implied that, while it was still being tested, this would be mandatory, destroying community trust. An absolutely flubbed rollout.
https://www.theverge.com/2019/10/15/20893343/meetup-users-fu...
https://wptavern.com/meetup-com-introduces-rsvp-fees-for-mem...