Wouldn't this strongly select for only desperately (for lack of a better word) lonely people? For everyone else, simply talking to strangers in real life is less friction than tackling some online quiz.
My thinking is talking to random people is... random. We can do this outside the internet, don't really need an app for that. Being able to prescreen is less friction than spending time meeting uninteresting people. And having no barriers seems to be a recipe for that in my experience, it attracts those who're desperate because they can't meet people any other way. So if I want a way to remove those people, I'd want to have a higher barrier, not lower. Is the idea flawed?
I don't know if it's a flaw per se, but you're not only removing uninteresting people, but also interesting people who aren't interested in taking online quizzes.
> Being able to prescreen is less friction than spending time meeting uninteresting people.
This is probably true for some individuals (e.g. those with social anxiety, or those who work 16 hours a day or something), but certainly not all. Even uninteresting people are often moderately entertaining for a short while, which is much more than I can say for taking an online quiz.
Additionally, there's a bit of a chicken-and-egg problem regarding the reputation of the group itself. If I can be pretty sure ahead of time that being admitted to the group will be worth it, then I will probably suck it up and take the quiz. This pretty much requires someone who is already a member convincing me. Otherwise it might well turn out to be a ghost town, or full of holier-than-thou nerds, or just not a fit for whatever other reason. I wouldn't want to go through a prescreening process just to find that out -- easier and more fun to just stick with meeting randos.