I mean, admin costs at hospitals are ~25%, around half of that is directly linked to billing. Administrative costs in the US (because of course you have the same costs on the other side in the insurance side) are around 30% of cost in general, which is pretty insane.
The lack of regulation around pricing transparency and generally the lack of one-price-per-code (which the government uses to its "advantage" to get lower medicaid/medicare rates for sure) is what has caused this stupid arms race on both sides.