The thing is they're currently trying to sell as a business oriented tool. They're not going to make money off of individuals.
Google is positioned to come closest because they're already an advertising company.

If you think their focus isn't businesses then you're not paying attention to their strategy. The pressure to drive profitability is increasing as their business customers are reporting that investment in AI capabilities isn't converting into measurable financial returns. That's the type of news that makes investors wary.

If you operate at a loss, you need to be providing a value to your customers that you can leverage. You need more than high interest, you also need demonstrable utility.

There have also been plenty of times that a new technology just ... Didn't pan out. This specifically happens with AI technology, and we even have a term for it: https://en.wikipedia.org/wiki/AI_winter The tech won't go away, it'll just be market infeasible for a while until it's no longer called AI and is just a feature in some other product.

Take your comment and apply it to someone marketing "spell check as a service".