> Or, has modern life done something to me that it has also done to everyone else?

it's a mix of life moves and mismatched schedules, as well as some people simply being flaky. It's hard to make friends if you're always moving around for your job, and jobs are less stable than ever (be it willfully with job hops, or unwillfully with layoffs). So it happens a lot more.

And yeah, I think "flake culture" makes it harder to form gatherings when you're still forming that friendship. Some people just have other stuff in life (be it in or out of their control), but they never bother communicating it. So with that radio silence, you can't do much.