The old money (journalists of mainstream newspapers) can leave and take all the audiences with them. Their audience is there for the narrative and ideology, not because they are fond of Twitter.

Twitter does not have a "native" audience, because it claims to be a platform. If they engaged deeper with content producers (like substack does) they might have. It's a solely megaphone, hence useless without a voice behind them.

Old money reigns supreme because the "new" voices are not independent. They go on twitter so they can graduate to mainstream media (or to onlyfans)