This is a weirdly cherry-picked example. The gaming approach was also the premise of DeepMind's AI efforts in 2016, which was nine years ago. Regardless of what you think about the utility of text (code), video, audio, and image generation, surely you think that their progress on the protein-folding problem and weather prediction have been useful to society?

What counts as a killer app to you? Can you name one?

Well the example came from their own press-release, so who cherry-picked it? Why should I name the next killer app ? Isnt that something that we just recognise the moment it shows up, like we did with www and e-commerce? Its not something a comittee staffed by a bunch of MBAs defines ahead of the time, as is currently the case with the use-cases that are being pushed into our faces every day. I would applaud and cheer if their efforts were focused on scientific problems that you mentioned. Unfortunately for us, this is not what the bean-counters heading all major tech corps see as useful. Do you honestly think any one of them has the benefit of society at heart? No, they want to make money by selling you bullshit products like e-mail summarising and such. Perhaps in the process also to get rid of software developers altogether as well. Then once we as the society lose the ability to do anything on our own, relying on these bullshit machines they gain not only in terms of being able to entshittify their products and squeeze that extra buck, but also opens a "world of possibilities" (for the rich) in terms of societal control. But sure, at least you will still have your, what is it now, two-day delivery from Amazon and a handholding tool to help you speak, write and do anything meaningful as a human being.

The whole idea of a "killer app" is stupid.

It is a dismissive rhetorical device to prove a wrong point on an internet forum such as this that has nothing to do with reality.