You can hold private companies accountable via secondary boycott. It's more complicated but it can be done.
'Are held' and 'can be done' are obscenely different to conflate them.
Correct. Also, you won’t be dragged to a keyboard connected to a computer logged in to Twitter at gunpoint, but you sure will be dragged to court to face a judge at gunpoint. There are different standards of accountability that match the standards of compulsion and violence.