I am skeptical about 4. There is a reason Meetup ate Facebook for many things despite it requiring a new account, Facebook groups are terrible and Meetup shows that you can compete.
A substantial number of people I know under 40, myself included, have deleted Facebook or logged off indefinitely (my spouse still has it so that’s how I found out.) The meetup I regularly attend that advertises on both platforms sees significant new attendees from meetup.com. It’s a shame the platform itself is falling into such disarray post-pandemic.
Think HN or lobste.rs vs....well, Facebook!