Partly because extreme self consciousness has become normal in the era where abnormalities can get you recorded and posted on the internet for mockery.

Like I get it, I have an anxiety disorder and cptsd and was bullied as a kid all of which combine to a form of extreme self consciousness. But my fear of playing my steam deck in a laundromat or on the bus is what's left of what was at a much less healthy stage of life a fear of going to the grocery store or browsing in a shop for more than exactly what I went in for (ok I still struggle with that one).

It's mental illness that certain corners of the internet, 4chan especially, have not only normalized, but gone so far as to encourage in each other and likely induce. Also given that it's 4chan it probably originates with self consciousness from failure to understand social rules and expectations and the policing of themselves extending to policing of others