Cable TV was first pitched as a method to get broadcast TV - with ads - in places that couldn’t get broadcast. Cable companies put big towers up and rebroadcasted network TV - with ads.
Then HBO came along as an ad free premium channel and it still is.
Then the “Superstations” like TBS out of Atlanta came along. Which were always ad supported and started broadcasting nationally.
Then the first cable channels came along like MTV, Lifetime, ESPN, USA. Not only dud they have ads from day one, they had infomercials to fill out the time when they didn’t have programming to show.
There has never been a time since the invention of cable TV in the US that it was ad free.
From a 1981 NYT article
> Although cable television was never conceived of as television without commercial interruption, there has been a widespread impression - among the public, at least -that cable would be supported largely by viewers' monthly subscription fees.
https://www.nytimes.com/1981/07/26/arts/will-cable-tv-be-inv...