fwiw this is how it's always been. You don't have to be some kind of extreme extrovert, but people who are good at what they do tend to enjoy working with other people who are good at what they do, and when they see someone they recognize as "I'd work with this guy again" they put in the minimal effort to stay in contact - a hello text every few months, a cup of coffee every few years, that type of thing. Thats all it takes. If you're not doing that, yeah, you're in for a world of hurt when you go job hunting.

>a hello text every few months, a cup of coffee every few years

sounds like hell to me