Even in the early 00s when I was in college everything seemed to have become lamer than it was just a decade prior. 20th century libertinism peaked in the 70s and has been in retreat since then.
This is certainly true, but it is also not the only source of the problems outlined in the essay (and by others in this discussion). It's this:
Stanford’s new social order offers a peek into the bureaucrat’s vision for America. It is a world without risk, genuine difference, or the kind of group connection that makes teenage boys want to rent bulldozers and build islands. It is a world largely without unencumbered joy; without the kind of cultural specificity that makes college, or the rest of life, particularly interesting.
And this isn't just university life. Read Matthew Crawford's The World Beyond Your Head and Why We Drive to get a sense of the ways that safety-ism is the new American way. As humans, we develop cognitively and emotionally when we are placed in risky situations (whether emotionally or physically). Perhaps it's college kids doing dumb things, or perhaps it's kids building bike jumps in the local park or homemade zip lines in the local park.
I agree with the 70s. The AIDS epidemic began in the 80s, which could have been a big reason. The wild and free way of life has been in retreat, and epidemics cause big chunks to be lost all at once. Maybe we'll look back on 2020s the same way: "Wow society was so wild and free up until the 2010s."