Having Discovery's awful content push out quality HBO content was already a major blow.
Yes, the price of one subscription. I think some cable packages in the US are $200 per month?
The only explanation I can think of is that most of the subscribers are elderly folks who signed up long time ago and didn’t bother to look into current bills.
Also maybe some ardent sport fans?
Another is broadband deployment. Choice is low in many parts of the country, and bundled service offerings are frequently priced near the "internet only" offerings to nudge customers into a "might as well" posture.
The only way to keep Internet/TV costs low is to threaten to cancel or switch every year, and actually be willing to do it. For some that isn't an option because there is only 1 provider, and others I've talked to hate that idea because you have to learn a new channel lineup. It's amazing how much people will pay to not be slightly inconvenienced.