You can make friends anywhere. Many people make them in situations like high school or college but there are other options like church, work, online, clubs, hobbies, bars, etc.

It seems like a stretch to blame society because specific people have poor social skills and can't attract a mate or friends. Putting them in social situations more common of the past doesn't mean they'd have any better luck. They lack skills that take trial and error and lots of practice that most other people learn at a young age. I know a couple of guys that could be considered incels and they lack self awareness, refuse to listen to advice, and spend nearly all their time playing games online. If they actively choose not to work at improving their deficiencies, whose fault is that? If someone is morbidly obese yet refuses to eat healthier and instead goes out to McDonald's for every meal, would you say the same thing? At the end of the day you have to take some responsibility for the situations that you find yourself stuck in. That's not to say these people deserve it, but we all have our own challenges in life that we must overcome.