This comment will get buried in the sea of individual responses here since I am too late. But for the dumpster divers, here is my contribution!

1. People have obscenely high standards for social interaction. If this person is not an outlier (in a good way) with their behaviors, it's just not going to happen. Most people have a very low tolerance for new people in their life. This has always existed to some degree but people today much prefer to listen to endless content from their favorite streamers, comedians, etc. and form parasocial relationships.

2. The environment for interacting with people has much higher stakes. Think about all the people who get recorded and posted on TikTok every single day. These are people doing it where you can see it - not just the Meta glasses people who remove the recording light. You can act like being a weirdo has no consequences but everyone has this extremely powerful device that can broadcast whatever you do to billions of people immediately - and you can suffer real consequences from this. Every crashout you have in any kind of crowd will be posted for eternity so that the world can see.

3. There is less and less benefit to having social networks/friends. Your friends aren't going to help you get a job, buy you a house, or meet your spouse. Meeting a spouse through friends is increasingly rare as online dating is dominating. As much as everyone complains, it is the major way people meet their spouse in major cities. People assume this is because friend networks are getting smaller but it's not due to that. It's because standards for interaction within friend groups has changed and standards for partners has changed. Unless you are prolific top 1% social maximizer, you are not going to run into anywhere near enough eligible people in your social network to meet your maximized match. We expect to completely maximize and find the best possible fit for our spouse now. Compromise of any kind is considered worse than dying alone. Cost of housing has exploded, jobs have become very hard to keep/find, and this turns everything into a transaction. Living with friends and kicking them out when they can't make rent is a tough but very real situation. People are more transactional because the economy dictates its necessities. Your family is the only thing that will bail you out - your friends can't overlook you skipping $2000/month in rent for 6 months.

There is more but anyway - loneliness epidemic is not going to get solved. It will continue to get worse until some kind of revolution which would require a complete reworking of our entire economy. I would accept this as the new normal and try to figure out how you can optimize your own individual experience in spite of all these things that are working against you. It is not worth trying to fight it on a systemic scale because there are simply too many components and the core cause is one our entire economy is based around. (A good investment is inherently counter to affordability)