Those are some really good questions that I don't have any definitive answers to. My guess is that in a patriarchy, men are still coded above women. Even though there's a hierarchy amongst gay men, there's not that same subconscious belief that certain ones existing for the pleasure and enjoyment of other men. (Correct me if I'm wrong about that).

From what I've read, there is an incel movement because it provides a huge sense of community that these guys had been missing in their lives. It's to the point that if someone who was well known in the community does get a girlfriend, they aren't happy for him - they vilify him for essentially betraying the very fucked up belief system where women are often viewed as subhuman. Elliot Rodger is considered almost godlike, and spoken of with much respect.

As far as what can be done, well, I'd say dismantle the patriarchal dominance hierarchy (but then I would say that, wouldn't I 😸) Their pain comes primarily from feeling at the bottom of that - remember, Rodger was bullied by other boys - but instead of blaming the hierarchy itself, these guys turn on women as the source of their problems - a dynamic that we see across the manosphere. Meanwhile, patriarchal norms of masculinity keep it from being OK to be vulnerable, to ask for help, to not be "tough" looking, etc. If we had a more egalitarian less domination-oriented social structure where more men felt comfortable supporting each other and being kind to each other, guys with insecurities could turn to their friends, rather than to incel communities.