It feels like a simple gesture, but it solved many issues at once:

- unless something urgent was scheduled over it, it was a period where you'd be sure you wouldn't be interrupting the lead, and are free to ask questions. You never felt like you were wasting their time, it's already baked into the schedule.

- There's a lot less friction just unmuting a mic and talking to a group than pinging a channel or sending a DM, but also a larger guaranteed of a prompt reply.

- it was an informal meeting half the time, so it was a good way to semi-organically team bond compared to leaving a huge paper trail of sports discussion in a team channel. It also means it's very easy to invite others in if their help is needed. A few times, it'd be a "talk" period where we'd invite another team and they use the time to share knowledge of what they are working on.

- even if you had nothing to help or help out with, it was a great way to shadow the work of others and get a feel for how the team overall is doing. The most underrated aspect of an office space is hearing all this tribal knowledge in the background as you work, or during a break. This helped a bit to bring that back.

- Breakout rooms. If there was 2-3 parallel discussions forming, we can simply divide the meeting up instead of going through that weird song and dance of prioritizing discussions (hopefully not dropping it entierly) or booking another room.

Some companies went the complete opposite extreme and more or less made it an obligation to stay on such a "meeting".

Text can solve some of these issues, but if the walky-talky was anything similar to our office hours, I can see the appeal. It could be a generational issue, but you just don't get much "idle chatter" in formal chatrooms in my experience. Some people absolutely love that and lets them work more focused. Others can start to feel isolated from the team and the mission, so that socialization can help break the ice.