Of all the things, I'd like to begin with the line saying "No high schooler ever had to to self-improve, etc.".
1) They assume "normal" people do certain things and have a certain mindset, without even talking with them (especially women);
2) They fail to realize that everyone in their teen or pre-teen years has done cringy shit in order to look cool, be popular, etc. Normal people don't "just exist and things happen to them": they get there by trial and error. The difference between them and an incel is that when normal people tread on the error part, they don't obsess over it for months; maybe they feel ashamed, but they don't go to the extreme of considering themselves a genetic dead end. They just go on trying to put the cringe behind them.
3) They assume they know perfectly what "normal people" think, assuming that normal people have no fears, doubts, etc.
Could they see themselves from the outside, deeply immersed in conjuring theories about genetic dead ends and incel science, they'd probably cringe themselves to an aneurysm.
(I know that this kind of incel shit doesn't need to be debunked, I just wanted to give my take on the image.)