Most people with > 3 jobs worth of experience will tell you that coworker-friends rarely transition to non-work friends after leaving said company. You will become too busy with making new coworker-friends at the new company, combined with non-work family/friend commitments filling the rest of your time.

One person with over 25 years in IT will tell you not to generalize. We're all different. I keep in touch with people i worked with 25 years ago, even across different countries and continents. I am a contractor so I change jobs roughly every year. I still go out with friends i met at work, and i have brought many of them into projects i started at other companies. I also have been hired by people i worked with previously. People are precious. The fact that you work with them 8 hours/day doesn't make them less so. I won't talk about the difficult ones, there's always that category too