I would need to see some sources on “They come from particular schools, live in particular cities...”
Even if this were true, (which I’m highly skeptical of) why would this even a bad thing? I mean, if we’re talking about elite papers such as The Wall Street Journal, The New York Times, Washington Post, etc.. it wouldn’t shock me at all to hear a number of them went to elite universities – a number elite doctors likely come from difficult medical schools.
I’m also not convinced “they” all share the same beliefs, not convinced of this at all. I mean, if you want to declare that media sources who prefer the Democratic party exist, sure but for every single one of those there’s at least one Fox “news” equivalent. The simple fact of their existence doesn’t mean certain people have a monopoly on information. This argument would be as ridiculous as when people in 2017 were screeching (US) liberals run the world all while the president, both congressional houses, and the supreme court were conservative... the concern wasn’t based in reality, at all, and it’s the same with their panicky “liberal news” conspiracies, I see no evidence which shows conservatives voices aren’t being heard, none.
Anyway, I’m dubious about the idea that almost all news people come from the same class, same schools, and same cities. Unless you’re simply saying elite journalists come from the best journalism schools, at which point it shouldn’t really surprise anyone.