The whole issue with LLM models right now is that they are notoriously difficult to control. If it were up to Google, every single response would include a reference to some sponsored content - but they can't do that without completely destroying the usefulness of the output and besmirching the sponsor's brand.
Of course, as time passes, we're going to refine this technology, until we have enough control to implement these terrible/profitable ideas. Like any aspect of life under capitalism, we can really only enjoy it while it lasts.
I hope at that point we have enough capable alternatives. Like, hopefully around the time they add ads is also the time when open-source models and apps have caught up again.