> I don't find it particularly sad if people mind their own business in the gym.

But that is part of the whole loneliness issue isn't it. I can certainly understand people wanting to just do their workout, but it's one less source of interaction between people. We don't talk to be people at the supermarket, we don't talk to people waiting for the bus, we'd rather listen to a podcast during our workout, than talk to the guy sitting on the next bench.

Very anecdotally: I'm fairly introvert, but have issues not talking, so I'll fairly regularly talk to random people. Some people will clearly prefer to be left alone, but frequently people smile and light up and start talking about all sorts of random stuff.