My employer of 23 years also employed a battery of accountants and a few lawyers.
Both contributed ZERO to making the product better, cheaper to produce or easier to sell. Just the contrary, both groups were a big drag on the bottom line. The accountants were necessary due to government requirements to figure exact taxes, depreciation etc. The lawyers were there to defend us against frivolous law suits, which they performed well. However again, it did not improve the product, make it more reliable, or cheaper to produce by 1 red cent.
If your company had no accountants, how would it know whether the processes it was using made it cheaper, or more expensive to produce the products? Would you have engineers spend part of their time tallying up things? If so, what would they call that task “accounting”? Would that have been the best use of engineers’ time? Would you trust creative engineers to with the detailed work of accounting? Is everyone capable of doing engineering work? If someone can’t do engineering, but could do the counting — wouldn’t it make sense to have some specialization of tasks?
(I’ve already said enough about dead-weight costs owing to government regulation. I don’t disagree with you there.)