Getting rid of administrators doesn't obviate the need to administrate. It has to be done, so we do it efficiently using shared resources, which brings economies of scale -- that efficiency Musk keeps talking about. What you're arguing for is increasing waste so everyone has less time to do critical work.
Here's an analogy:
To support the roof of a house, you need a few support beams. To support the roof of a skyscraper, you need many more support beams. You can't support the roof of a skyscraper with the number of support beams that support the roof of a house.
University research started as a house, but now it's a sky scraper. You're coming into the skyscraper saying there's too many beams, but you're judging by house standards. Maybe there are, but most of them were put there for good, well-considered reasons; as a layman you have no idea which are load bearing, so if you come knocking them down you endanger the whole tower. Which is a shame because it's gotten really really tall - taller than any other tower in history - so toppling it because you don't understand it would be a huge loss for everyone.
Given that my comments are downvoted like crazy, I've got the feeling that the US university including the Professors (tenured) are missing the forest from the trees regarding this issue.
I once asked a senior and prominent US Professor regarding their multi-million dollars grant for single project that can be easily spent on multi-project with similar or higher impact in other countries. His answer was they have to spent a lot on students, and now I know the truth that most of the money are going to the research managers and admin staff, what as waste.
This is a good thing. It's expensive to support a Ph.D. student in America; it's a lot cheaper if you're in a country with lower cost of living. But as a researcher, you want to do research in an expensive area because it means you'll be around other smart people and lots of resources.
At the end of the day tho, despite all its flaws, this system is a winner; US produces the most research, is home to the best universities, and students from around the world dream of studying in America. We can make improvements, but the need for a rewrite of the system is greatly overstated. Other countries wish they had our problems.