Comment by tern
A major factor in my world: the coolest people don't use dating apps because they find the experience awful and they have no problem meeting people in real life
The spicier version: dating apps select for personality disorders, and as such, being on a dating app in the first place is a negative signal
For what it's worth, I think this has always been true of the web in general (forums, chat, social media, comments sections, etc.)
It's even more stark if you weight it by sampling online content rather than a sample of people online (who are mostly lurkers). Certain types of people tend to post a LOT, so a random sample of online content will be biased towards the "high posting frequency" type of person, who is probably not a normal average type of person.