In my experience, any meetup > 10 people becomes useless because you cannot really make meaningful connections and large meetups usually have a fixed agenda where everyone is out there selling their own stuff.
I now will not attend a meetup unless it is extremely small group (<10 people). Those are hard to sustain though.
Speed meetups could work where you'd go to a series of meetups in a row. Venues could allocate space for this, say 5 separate rooms and every few months you'd go to a bunch of meetups all on the same day. Small gatherings with a larger space where people could keep talking once the set period is over if need be.
Even a local park on a sunny day would work and you could "kick on" into the night if things were going well - no obligations or pressure.
this. the meetups i was a part of devolved into product pitches and people looking for jobs
The coworking space I was at back in 2013 held regular weekly meetups in the common space. Sometimes cool tech was shown off, but a ton of promo talks was common. I won't say no to free pizza though.
Sounds like the same problem with <activity> meetups. Some people are there for dating, some people are there for <activity>.
Thing is, people have to realize this because mixing the two leads to misery.
Maybe they have to be explicitly told not to put their foot in it.