- DoD / DoW is a chaotic project owner, trying to squeeze in colossal and sometimes self-contradictory lists of requirements, which it wants to change often.

- The US government is a poor customer, which runs out of money from time to time.

- The US Congress is a cantankerous financier, which haggles for the money every year, and demands the production to be distributed all over the place, to bring jobs to the constituencies which voted for the congresspersons.

- The companies that produce this stuff are few and mostly cannot be easily replaced, and they know it. This is because in the late 1980s the US government decided that it has won the Cold War and will not need the many competing manufacturers of military gear any more. That proved to be a bit shortsighted, but now it's a bit late.

I think that mostly means money is cheap in China. In America, if you try to start a humanoid robot company you'll immediately run into the "Why though?" question when you try to get money for it. The case for the economic relevance of humanoid robots is dubious at best, so to proceed with such a development program you need your own money or at least good friends with connections who don't care about money.