While I did go out to lunch with coworkers more often while working in the office it was almost exclusively with direct teammates, and other groups I occasionally saw where also on the same team.
Now that I'm fully remote, I will typically do a few "hacking sessions" over Zoom every week. Its much easier and more comfortable than standing over their shoulder in tiny cubes we used to have.
That said, especially now that i am fully remote, I've been trying and mostly failing to get developers especially across teams to talk and collaborate more. But its not too suprising: I was recently in a call and I was introduced to another developer who I replied, "Yeah, I know you. I was in the cube next to you for 2 years and on your team for 6 months."
Remote creates some new challenges, but its a culture thing, not a technology thing.