There's two things I'd love to know how you're thinking about:
1. Right now, the benefit of Meetup is natural discoverability. I can set and forget an event with no advertising and people will find it and show up. That's not true of any of the other event websites. This may be specific to the Austin community though.
For example, I've tried to post the professional data happy hour on LinkedIn events, Eventbrite, and Meetup. Meetup always drove >60% of the ~50 attendees.
I've been increasingly interested in Luma because they have the idea of a "Calendar" you can subscribe to which doesn't require the origin of the event to be on Luma itself. This allows it act as an event aggregator while still encouraging events to originate on Luma with notifications and reminders built in. See an example here: https://lu.ma/austin-tech-scene
How are you thinking about becoming a go-to resource for discoverability?
2. It's my understanding that despite the high cost to run Meetups, the company itself has never been in a good financial position. They've been bought and sold multiple times.
How do you plan to make money? Without a visible monetization model, my main concern switching to your platform would be the longevity of the platform and the risk of building up an audience there.