I feel the same argument can be make about Tor. While it primary uses are probably illegal (doesn't necessary mean immoral) activity, it helps a lot free press in oppressed regimes (also illegal, but by western standards moral).
I very much doubt that. Its primary uses are probably porn and researching embarrassing medical conditions.
And TOR is rarely used. Journalists use apps like Signal now.
Absolutely not. Internet censorship is growing rapidly - worldwide.
A lot of "legitimate" websites like newspapers get blocked around the world and can only be accessed over Tor.
Signal does not let public fund jurnalists.