this is exactly what they do, if you pay for your account, you don't see ads

As of November 2025, no ChatGPT tier is profitable, not even the $200 a month one:

https://futurism.com/artificial-intelligence/sam-altman-lose...

That doesn't scale in the world of capitalism. Because you need to increase revenues year after year and there are only so many people willing to pay. So you either keep increasing the price (and that has a limit) or you find other ways to monetize and the current meta seems to be pay + ads.