It is easy to see when a machine gets complex, somewhere something will go wrong. It is like a gear box, there are many big and small gears. All of them needs grease, more and more grease. If even a small gear gets locked, the whole box stuck.
Government, company, economy are the same. When it gets too many departments, too many functions, they needs increase amount of greases (money), the complexed government and economy will eventually stuck, because there is no unlimited grease to keep them working. Very simple, isnt it.