And how does making me wait until the very end of my slot help any of that?
It probably doesn't help much. I work at EUROCONTROL and, IMHO, direct routes are a bliss. The shorter time you spend in my airspace the better, the sooner I'm done and can move on to the next. However that's about to change, since we're reaching TFC levels that some sectors just can't cope with. And unfortunately keeping accurate track of those almost 5000 flights a day is impossible. We have some reasonable good tools for it but none is perfect. But that's also only in our case. It is also a bit selfish, since we are told we may be contributing in some cases to create congestions at the destination airports (one of the reasons you won't get direct to final from 300NM away during the day unless you fly to a very small airfield) We do not deal with airports directly and there's the pickle. Airports are the bottlenecks really. If an airport can only handle 80 movements an hour, that 100 aircraft arrive/wanna take off in an hour just causes delays and congestion. In theory CFMU should avoid that. Then life happens, but also I understand that is no excuse to just ditch the system altogether. As I tried to get across, controllers in Spain are way overworked, and are falling back to basics. Not justifying that, just stating it. But then again, sometimes when working close to the limit, I tend to do the same (and it works for me). Imagine you had to operate on your own, you'd probably need the full 10NM approach every time. Can't be preparing for landing, talking the R/T and flying the plane and be expected to do acrobatics at the same time (if you can do it, good for you, but not everybody can and it is not the way it should be done anyway).
Wishing you guys blue skies and safe landings,
A.