The one that comes to mind is the airline deregulation of the 1970s. It phased out one regulatory body without institution of new powers upon the others.
I'm not sure what you're talking about. Airline deregulation didn't make it harder to start a new airline--to the contrary, lots of new airlines were started after deregulation.
https://en.m.wikipedia.org/wiki/Airline_Deregulation_Act