The likes of itch.io, Roblox, and the App Store already exist, each with more games than anyone can reasonably curate.
The games market has been in the same place as the rest of the arts for some time now: if you want to be noticed, you have to mount a bit of a production around it, add layers of design effort, and find a marketing funnel for that particular audience. The days of just making a Pong clone passed in the 1970's.
What technology has done to the arts, historically, is add either more precision or more repeatability. The relationship to production and arts as a business maps to what kinds of capital-and-labor-intensive endeavors leverage the tech.
Photographs didn't end painting, they ended painting as the ideal of precisely representational art. In the classical era, just before the tech was good enough to switch, painting was a process of carefully staging a scene with actors and sketching it using a camera obscura to trace details, then transferring the result to your canvas. Afterwards, the exact scene could be generated precisely in a photo, and so a more candid, informal method became possible both through using photographs directly and using them as reference. As well, exact copies of photographs could be manufactured. What changed was that you had a repeatable way of getting a precise result, and so getting the precision or the product itself became uninteresting. But what happened next was that movies and comics were invented, and they brought us back to a place of needing production: staged scenes, large quantities of film or illustration, etc.
With generative AI, you are getting a clip art tool - a highly repeatable way of getting a generic result. If you want the design to be specific, you still have to stage it with a photograph, model it as a scene, or draw it yourself using illustration techniques.
And so the next step in the marketplace is simply in finding the approach to a production that will be differentiating with AI - the equivalent of movies to photography. This collapses not the indie space - because they never could afford productions to begin with - but existing modes of mobile gaming, because they were leveraging the old production framework. Nobody has need of microtransaction cosmetics if they can generate the look they want.
