Check Airman
But we should be paid the big bucks because we know HOW MUCH fuel to take and HOW TO AVOID the terrain. Slightly on tangent, I also think that we should be paid the moment we turn up for duty. In my opinion, preflight decisions on route, altitude, fuel, alternates and thrust derates are just as important as knowing when to turn to intercept the LOC and where to start the descent.
Just acting as devil advocate I would say that basically all flight planning and performance calculation computer systems will tell you about "how much fuel, route, altitude, fuel, alternates and thrust derates". And actually what you are doing at preflight is checking printouts agains latest weather and applying your previous route experience to decide whether the printout is correct or "let's uplift 700 USG more just for mum".