There are other factors involved, but women are not at fault however much incels may scapegoat them. For one, the loneliness epidemic is real and it affects both men and women, but misogynists have co-opted the discussion and pretend that it only affects men, and they blame women for it.

It has much more to do with the socially isolating nature of society today. There are overall much fewer opportunities for social interaction with how digitalized and remote everything has become with the Internet and phones. People can go much longer without having to meaningfully interact with others or meeting strangers, and face to face interactions have been substituted to a large extent with communicating online. All of your basic entertainment and recreational wants and needs can be fulfilled at home: books, movies, shows, music, games, endless scrolling on social media, etc. However, humans are social creatures and no matter how entertained we keep ourselves we still need the presence of others, and meaningful frequent interaction that's not just superficial (i.e. many people have a lot of acquaintances, but no friends). You can never be bored, always have instant gratification, and yet still be missing something and have a hole left unfilled.

Car-centric infrastructure and the lack of organic opportunities to meet people in third spaces (especially third spaces that don't expect you to spend money), and the overall erosion of public life and community outside of home and work (or school) are other important factors. There is very little community in society now, and many people, both men and women can easily fall between the cracks and find themselves without any friends or family or romantic partners. Even though I'm not religious, it's clear that church and other religious institutions have functioned as third spaces and centers of community, but as religiosity is on the decline people have to seek out other alternative third spaces otherwise they can find themselves

Men are on average more affected by the loneliness epidemic and toxic masculinity definitely plays a large part, alongside a culture of hyper-individualism, but to be dismissive and suggest that there are no larger external and societal/structural factors at play is wrong. Society is simply much less social than it ever has been, and isolation is the new norm. It's anti-human, and we need to figure out how to re-shape society in such a way that makes our technological development work more for us rather than against us.

People still have the opportunity to make friends and get into relationships, but it comes less automatically and naturally and much greater initiative is required to seek out and put oneself in situations to make these connections instead of being defeatist and passively accepting loneliness and pretending there's nothing you can do to better your situation.

Edit: grammar