Ditch AIRWAYS and fly DIRECT, wonderful in theory, just try to get the military to agree.
I wish I have a penny for every wasted mile flown by airlines going around "active" areas in the North Sea which were actually empty.
As for SIDS and STARS, even with the latest generation of very quiet aircraft, try to convince the NIMBY brigade, even though they are the most likely to be those actually flying from their local airport.
Luckily for me, those frustrations ended a year ago, but I am sure my PC colleagues have exactly the same issues on a daily basis