This is what makes this technology anxiety inducing at best...
So, for yourself, you have no issues seeing the artificiality of the image due to your extensive exposure to and knowledge of photographic principles. This is fair... that said, I have read your earlier comment about the various issues with the photo as well as this one about light sources, and I keep going back to scrutinize those elements, and... for the life of me... I cannot pick out anything in the image that, to me, absolutely screams artificial.
I'm fairly sure most people who look at these verification photos would be in a similar boat to me. Unless there's something glaringly obvious (malformed hands, eyes in the wrong place, a sudden cthulhu-esk eldritch thing unnaturally prowling the background holding a stuffed teddy bear) I feel most people would accept an image like this at face value. Alternatively, you'll get those same people so paranoid about AI generated fakes they'll falsely flag a real image as fake because of one or two elements they can't see clearly or have never seen before.
And this is only the infancy of AI generated art. Every year it gets better. In a decade, unless there are some heavy limitations on how the AI is trained (of which, only public models would ever really have these limitations as private models would train be trained on whatever their developers saw fit... to shreds with what artists and copyright said), there would probably be no real way to tell a real image from a fake out apart at all... photographic principals and all.
Interesting times :D
To start with, you're right. Digital distribution in general is volatile for consumers. While I will say that Steam, at present, is leagues better in that you must download the game purchase in order to play it (meaning, you have a direct copy of the game on your hard drive, which will remain there even if the game is removed from the Steam store), it is not outside the realm of possibility that this could change in the future.
That said, publishers having their own launchers, I'm sorry to say, has absolutely nothing to do with their fears over "the valve guy" retiring (his name is Gabe Newell, by the way), and significantly more to do with making more money. These publishers figure if they can get you, the consumer, to buy their games directly from them, they can make 100%+ of the money, instead of having to pay Steam a percentage for any transaction. Due to the limited scope of these Publisher-run launchers, purchasing a game from them is even more volatile than purchasing from Steam (at least in the current climate), in such that if the Publisher suddenly finds their launcher is not bringing in customers (which, on average, compared to the draw of Steam at present, they generally don't) publishers could simply drop their launchers and the catalog of games you, the customer, may have purchased from that launcher would go with them... again, yes, this could happen if Steam went down, but presently, pound for pound, the publisher's launchers are far more likely to fall than Steam will.
Also... for any of these services (Steam or publisher launchers), you have to download the game locally in order to run them. The games are not streaming as most movie and music content is. As such, once you install a game, you could crack them to remove any DRM attached to them (barring any game that's strictly online), then, yeah, you can self-host/store these games yourself all you want. If you buy games from GOG they make this even easier for you.