I don't agree with that statement, except in a relative measurement sort of way.
Back then there were only three TV news organizations, and they were all measured relative to each other, not measured relative to the truth of their reports.
It wasn't until Rush appeared on the scene that the element of truth was included in the publics judgment of how 'prestigious' these news readers were.
With the benefit of hindsight, we can see that NBC and others weren't prestigious at all, they were simply liars who kept getting away with reading lies to their viewer night after night.
I thoroughly agree, it is a relative comparison and I am the first to credit Rush with restoring truth to the airwaves...If it weren’t for Roger Ailes and his syndicators we would still be awash in spin..