It is true that Cronkite, et al, were probably just as biased back then, It's just that, back then, people had no alternative. We do now.
Back then we listened to talk radio: Carl Mc Intyre, Dan Smoot, Dean Clarence Manion, Fulton Lewis Jr, Billy James Hargis. Smoot and Manion were extremely fact based and logical. Hargis and Mc Intyre mixed lies, paranoia and wishful thinking with the truth.
Talk radio changed when Jimmy Carter’s judge Green broke up Ma Bell and the baby bells competed on price. The talk became 2 way.