If it’s in a setting where open conversations are normal, then I think it’s fine as long as their speaker volume isn’t louder than any other normal conversation. To me, there’s no difference between two people talking in person and two people talking over the phone.
If someone doesn’t want to hold it to their ear because they want to video call or just browse their phone while they talk, I don’t see the problem.
This sounds like it would hurt Reddit more than the users since a lot of value was in being able to search archived solutions to obscure problems.
I’ll recommend a few from different genres: