How the forget can you have fun with people over the internet, especially if they don't have mics or cameras?
Because they aren't autistic and don't have trouble noticing the nearly nonexistent blur between physical and media communication. You are still communicating with humans, even without the microphones and cameras. You know that something sapient is behind that soldier dude, which is why agaro.io is fun.
You get to meet, play and socialize with people that you
wouldn't have been able to meet with. This is why this is such a popular thing in the past few years. We, as a social species, will do anything short of dying in order to communicating with one another.
It isn't because people realized that it is expensive and so-very-hard to get good story writers (your fat game developer e-peen is really showing in this one, Job), it is just because people like to experience something different than split-screening and doing missions with non-player characters.