It's also impossible to get 100% utility out of any supercomputer on the top 500 list. The overhead required to manage so many processors requires software running on many processors themselves. The "computer" is only "super" if you can give it something massively-parallel to work on. There are many problems that are not well suited for that.

The Chinese are using many slow AMD processors that use less power than Intel. The USA uses faster Intel cores for many of its top 500 entries, and it gets greater UTILITY per supercomputer than China can achieve at present.

It's like China has bigger airplanes, but makes fewer flights with most seats unfilled.