- Companies have generally tightened belts on discretionary spending, which means fewer people are being paid to go to conferences and events. Many workplaces offered a relatively free hand when it came to company-sponsored conference trips, but now you're not only looking at paying your own way but taking PTO to do it!
- As someone who still makes an effort with in-person meetups: space is so hard to get unless you're well-funded. There used to be a plethora of startups around here that were happy to let you use their office after hours, but the end of ZIRP and the ensuing belt-tightening has taken a lot of these places off the list.
- AI has sucked so much air out of the room. AI-related meetups around here are still pretty common, lots of VC-funded AI startups lending their space to AI-related meetups. Heck, many even have a food and drinks budget. But if you're in any space that isn't AI this kind of support is basically completely non-existent.
Also, I think a major factor that can't be discounted are incentives for speakers. For the same reason most companies have switched to recorded announcements vs. live stage announcements, speakers are incentivized towards remote/recorded events vs. in-person since the content has much wider reach. It may be less useful for the in-person participants but you're optimizing for the long tail of people viewing remotely/viewing later.