That's the optimistic take. I have a much more pessimistic take: there is now only one place where people who want to sell dental devices have to focus their efforts. Less effort for them... and because of the scale... much bigger payoff.

When I was thinking of the examples I gave (poison the training and/or pay the providers), I was intentionally drawing analogs to how I saw Google search decline.

First, SEO "experts" poisoned the results. Then Google saw how much money could be made, and they sold the ad space directly to marketers. If you search for "Best <widget> for <doing something>" on Google, I am certain you are not getting the "correct" answer. And Google has suffered no consequences for this. To the contrary: it has been extremely lucrative.