Sometimes people mix up the order of things and thus the cause and effect. For instance, with some medical issues, doctors have thought things like "oh, you went on this extreme diet, then you lost weight and had gastric issues". No, I lost weight and had gastric issues, so I went on an extreme diet. In this case, i think the misogyny precedes lack of success at finding a partner. It can also be a situation of giving up too soon. For me, middle school and high school were so horrible in various ways that i assumed I was 100% doomed - I didn't realize that life after 20 is very different. It still has high school social aspects, but it's a lot better in many ways.
If I hadn't met my wife 30+ years ago, I can see how I might have become a sort of paleo-proto-incel...maybe just more of a bitter old maid of a man that no woman would want to be around. I do feel for the incels. They certainly aren't happy. There's something unhealthy about a society that produces so damn many of them.
Personally I think not enough attention is paid to how community atomization and sprawl, and the near elimination of the third place in America, has fostered a crisis of loneliness.
Young men chronically have no outlets through which they can socially interact with women. The only place it happened was at school and maybe some extracurriculars if they were especially social.
Society unconsciously brushes this crisis off with "well the real friends that matter are the ones you make in college anyways!" Ignoring how that doesn't help guys that don't have higher study in their life plan, or the fact that learning to properly socialize is kinda the point of those grade school friends you'll probably lose touch with in adulthood.
All that was the case even BEFORE the pandemic hit, now even school's been atomized, granted, rightfully so in the circumstances, with classes going virtual and leaving students in a situation where the Internet is the only place left in the world where they can learn any social skills, and that's where the damned redcaps and chuds swoop in to prey on their insecurities.
So if I understand correctly, the study suggests the driving factor might well be longing for social dominance and sociopathic traits and not necessarily sexual frustration.
My theory that a rising number of men end up being Incels is that it's getting harder and harder for young men to make any experience with women at all.
Online and offline dating became toxic af which leads to frustration.
This frustration opens the door for people like Andrew Tate.
The article from OP says the most misogynistic men are ironically the ones which get laid the most. I'd put Andrew Tate into this category.
Sexual frustration comes from mysgonstic talking points that women, rightfully, keep their distance from. Why would I want to sleep with someone who is demeaning and insulting to me? 😂
My running theory is most of these people are queer to some degree. They end up hating women because they don't have the communication skills to express what they want out of a relationship. When they become unfulfilled then they blame it on the person they think is supposed to be fulfilling them. Sorry boys if you want your SO to peg and domme you you need to tell them.