You already can, check out Marble/World Labs, Meshy, and others.
It's not really as much of a boon as you'd think though, since throwing together a 3D model is not the bottleneck to making a sellable video game. You've had model marketplaces for a long time now.
> It's not really as much of a boon as you'd think though
It is for filmmaking! They're perfect for constructing consistent sets and blocking out how your actors and props are positioned. You can freely position the camera, control the depth of field, and then storyboard your entire scene I2V.
Example of doing this with Marble: https://www.youtube.com/watch?v=wJCJYdGdpHg
This I definitely agree with, before you had to massage the I2I and now you can just drag the camera.
Marble definitely changes the game if the game is "move the camera", just most people would not consider that a game (but hey there's probably a good game idea in there!)
It definitely is. Model marketplaces don’t have ready to go custom models for a custom game. You have to pay a real person a significant amount of money for 100s of a models a truly custom game requires.