Who is doing all the work of making physical agents that can behave as good as a UBI generator? Something that can not just create videos, but go get groceries(hell grow my food), help a construction worker lay down tiling, help a nurse fetch supplies.

https://www.figure.ai/ does not exist yet, at least not for the masses. Why are Meta and Google just building the next coder and not the next robot?

Its because those problem are at the bottom of the economic ladder. But they have the money for it and it would create so much abundance, it would crash the cost of living and free up human labor to imagine and do things more creatively than whatever Veo 4 can ever do.