Economics is also an underlying hidden reason behind everything. Making friends requires a lot of bandwidth. You cannot create them over a coffee or wine, it would be a multiple touch point event over 6-12 months. In low trust environments the cost of friendship goes up.

When you have to work 100 hrs a work to meet your expenses can you take out 20 hrs for friends. then another 20 for family, another 20 for kid. and then 1000 for your wife.

Inflation makes you work harder for the same amount. When everybody is working harder they don't have time. Also because they are not doing many things outside of work what will they talk about.

Rich people still find it pretty ease to make friends. The parallel processing of earning money, family and friends is really hard and eventually will take your stress higher levels than lower.