Comment by jakeogh

I get how you could miss that "based" was not being used in the context you expected, although the period after it instead of "in" or "on" should be a clue, now you want me to explain GenZ? It's a demographic group. Like GenX.

https://en.wikipedia.org/wiki/Generation_Z

"Gen Z is pretty based." translates to: "I, in general, like the way Gen Z is turning out."