I don't consider myself a reactionary, but I found Moldbug's "Open Letter to Progressives" to be a very convincing teardown of modern western society. For me, it made a lot of things 'click', and really drove home just how arbitrary and historically motivated present day beliefs are. I wouldn't say it shattered my world view, but it certainly gave me an outside view and I highly recommend reading it all.

He then follows up this teardown with a buildup of a reactionary perspective. I think he does an awful job of showing this perspective as any less arbitrary than the one he just broke down, and has very little real justification. But to someone who was just left with a despairing sense of uncertainty about how the world should work, I suppose that it would be very tempting to latch onto the first thing that could fill that hole.