People are dangerous.
I mean, most people are pretty okay. But there are a few who are not, and you probably only find out after you meet them. And it seems like meeting people is good on average, until you meet someone who may be a 1 in 1000 kind of personality, but does damage that outweighs the benefits of meeting 1000 nice strangers.
One approach is a naive "what could possibly happen?" and keep meeting strangers... and maybe you get lucky and tell everyone that the fear is exaggerated... or maybe you get burned, hopefully survive, and change your policy.
Only meeting people who are already vetted by others is a defense policy. You still get to meet people. Only fewer. But the risk is also smaller. Whether the overall outcome is positive... depends on the quality of vetting. Some people are happy to introduce someone they only met a week ago as a friend. You need to ask specific additional questions, to figure out how much such recommendation is worth.
This get worse by memes like "you shouldn't judge people" (one of the few things both conservative religious and progressive woke people seem to agree on -- you should not provide negative information on people either because Jesus would frown at you, or because if the person happens to be X then criticizing them is X-phobic). Judging people is actually the point. The ideal outcome is judging them precisely.
Oh, and if you judge people precisely, and they don't like the verdict, they may sue you. So judging others is not only difficult, but also dangerous. Better done privately in a deniable way, but of course that doesn't scale.
I am not aware of a good solution. Even companies have a problem judging their employees, and there is a financial incentive to get this right.
Besides the well-repeated "lack of (free) third places", and the sense that connection is being monetized online (and the feeling of disturbing mini-dystopian "we have online to connect everyone but we are more isolated than ever"), there's also the problem of people "not mentally up for" making a connection (going to work, home, at night, etc.) that makes people less receptive than usual, whatever 'usual' would be. The main difference in a stranger and someone you may meet for the first time is so contextual too, it's just abnormal to convey the same information of blurting out all your interests and status to a stranger (which still doesn't capture integrity of a person anyway).
People are often wanting to meet other people. And other people are everywhere. But everybody want to meet specific kinds of other people, and that makes things much trickier.
For one thing, you have to avoid all those people you don’t want to meet, which means not just accepting bids from strangers on the street. For another, reciprocally, you have to get past everyone else’s screening processes—that is, somehow distinguish yourself from a stranger on the street.
Consequently, the streets are full of lonely people, including many who would like each other, but can’t meet for lack of a good screening process that would identify them to one another.
In the old days and other cultures, the low bandwidth screening processes are an even bigger impediment to meeting people than now. For instance, it was improper to greet someone at a party without being formally introduced by an appropriate person.
In the future, if we manage to keep using AI without catastrophe, I wonder if it could herald a world of very high bandwidth screening processes, where you could just happily meet people on the street all the time, in any case where you are properly introduced by an appropriate AI system.