I'm extroverted, actually. We have several slack channels for each of the departments and hierarchies of our org. People say good morning. You can "go down the hall" and ask a question. We still do pair programming. In short, not much has changed from when we were in the office.

Once allowed we'll be going out to lunch again. I always made it a point to go out to lunch with people - people I work with now, people I've worked with in the past, and people I've met through meetups. I like going out at a minimum every other week and prefer once a week.

Maybe it's company culture? We're in multiple states and have multiple locations within the same state - and I need to work with people from all these different locations and so we've solved this "working together remotely" problems ages ago. It's an important part of our corporate culture. WFH just solved the problem of working in a big, noisy area.