No, Google takes money to present ads to people of different demographics, and uses your data to do that. It doesn’t sell your data, which is, in fact their competitive edge in ads – selling your data would be selling the cow when they’d prefer to sell the milk.

But it doesn't, does it? It sells the fact that it knows everything about everyone and can get the ad to the perfect people for it. It's not going on the open market and telling people I regularly buy 12 lbs of marshmallow fluff and then use it in videos I keep on my google drive.

In other words, having been burnt once by touching a flame, the conclusion these people draw is that the problem was with that particular flame and they're fine with reaching for a different one?

Even if they are not doing it now(?), what makes you think that they will not do so in the future? It's not like your data has an expiration date.

I see no reason to think OpenAI would leave that money on the table.

If it uses user data to train their models other users could ask "Show me the code for gmail spam filters", and if it was trained on engineers refactoring that spam filter in ChatGPT chances are it would give you the code. If that doesn't count as "selling user data" I don't know what is. They not only sell it, they nicely package and rewrite it to make it easy to avoid copyright claims!