I agree with this point to some extent, but now there's local #Bitcoin and #Nostr meetups happening where you're more likely to find that.

Conferences are like Twitter. Everyone is trying to shout "Look at me!" louder than their peers. 

 Point taken, I think the scale and ROI is what makes the conference attractive, you spend X your reach is Y since its a collaborative effort of marketing for it and on the day, with meetups its a constant churn