Cable was first introduced as a means to get over the air channels for remote places that couldn’t get a signal to get network tv. These channels always had ads.

Then came the “Superstations”. They were local independent ad supported channels like TBS in Atlanta and WGN in Chicago that went national. They always had ads.

Then the early cable channels like ESPN, the precursor to Lifetime, CNN etc and they always had ads. The other early cable channels were trying to sell ads to advertisers from day one but they didn’t have enough viewers.

Yes channels that you paid extra for like HBO didn’t have ads and still don’t.