I think the point I’m trying to make, albeit very bluntly is people often make the banal point that kids these days are too sheltered because they turned out fine. But they’re actually just observing survivorship bias.

The person you replied to didn't mention their own life at all, and they were talking about a good number of data points. That's not "just survivorship bias". The data of college kids is biased in some ways but it's not useless.

How to avoid that survivorship bias though?

I'm sure a study can follow kids or look in records, but that takes serious time, so I can understand looking at oneself and everyone you know and coming to a conclusion that way. Do you know if such a study had been done and the results or conclusions are publicly available somewhere?