HBO never had a tier with ads when it was on cable, it was simply expensive.
That was 80s Reagan/conservative American. Those folks weren't as greedy as modern day companies and they cared about their product/experience, whereas nowadays caring about that is outsourced (see the Mad Men mess) and greed is king.
It's wild to long for the day of 'caring', 'sane', Reagan era corporate 'governance'.
Lots of things didn't have ads on the past (basic cable TV for example). Today the model has changed to being expensive and still collect data/push ads. This isn't a cable vs streaming thing, it's a then vs now thing.