I may be biased due to getting older and having a family, so I'd expect to hang out after work less anyway, but I observe that generally amongst younger colleagues too.
At my third job between 2008-2012, I keep in touch with one guy that followed me across two more jobs until 2015. We try to meet along with one of my coworkers from my third job at least once per quarter.
I also met my second and current wife at my third job. But I can’t honestly say whether I would have tried dating her if I hadn’t known that the company we worked at was about to go under anyway.
I had a Slack group where I kept in touch with 5 of my coworkers from my 5th job between 2014-2016. But that died off.
When I go back to my home state, I am going to try to connect with my former CTO and a couple of other people from my 7th job (2018-2020). My former CTO reaches out to me every now and then and we talk. I owe him, he gave me a chance to lead their “cloud native initiatives” and hired me even though I had never opened the AWS console at the time. But he thought “I had some good ideas” even though he knew I had just watched a video and went through a certification training.
Now that I work remotely at AWS in the consulting department, there isn’t anyone I consider a “friend”, but one person who I worked with from the time they were an intern when I was their mentor.
The “team” I work with changes dynamically based on the project.
I also see “acquaintances” keeping in touch with ex-colleagues on some social media sites, so I know Im not an exception.
I appreciate “most” isnt all, but your comment is very different to my decade of experience. Work is a great place to form friendships.