Google trends + exchanges volume + etf volume, pretty easy formula for raw estimate
I think historically Google Trends has been an excellent way to see with data whether or not the average person is looking into Bitcoin. Currently it's almost like Bitcoin is still at the cycle lows the way it's being ignored by the average person. I think a lot of people got burned in 2021 and won't give Bitcoin a second look as a result, but there are still plenty of young folks who are stacking and being introduced to crypto at younger and younger ages. I think we probably have a year or slightly longer before Google Trends maxes out in it's Bitcoin searches, but when it happens I don't think you'll need to go searching for ways to see it.
I initially started this thread because I had a lot of guys around me asking me about BTC. They were here in 2021 and they are again here now. So it got me worried whether retail is already FOMOing in.

But got your point, people that got burned will be very careful this cycle.