Baron, you are barking at the wrong tree. I spend my all carreer ( passed in Maastricht UAC) giving directs and Req levels whenever I could because that was our culture then. Also, when I am busy, the earliest you are gone from my frequency the better it is for me. So we have a common interest there.Controllers generally do not like ATFM restrictions. It add to their workload.
Problem is that when the hub system sarted , you were sent to holding patterns in your arr airport quite often .1 hour holding in FRA or LHR on a Monday morning was common then .
The game changed when the airlines did not want to hold in the air anymore but on the ground.That was cheaper. ATFM was born. It is not an ATC invention to bother you , it was an " Aircraft Operators urgent need " as ICAO called it back then.
Comparing the US situation with Europe is pointless in many ways. Also ATFM , in the US 90% of restrictions are due to Weather 10% "volume" as they call it, In Europe it is almost excatly the opposite. Build more airports and more runways and get rid of the military airspace around civil airports in Europe and we can talk again .