True, but it takes around 45 minutes to prepare a plane for flight and about 20 minutes to put it away. Also, you have to drive to and from the airport. Planes are incredible, but you have to fly pretty far before they're a timesaver.
Where did those numbers come from? Preflight and run-up can be done in 20 minutes once you've done it many times and securing after a flight is as simple as turning everything off and pushing the plane in the hanger or parking on the pad. That's maybe 10 minutes at most.
The only really time consuming part would be making and filing a flight plan. If you've done the route multiple times, you already have the flight plan and if you're operating under VFR (visual flight rules), you don't need to open/close it.
Source: I'm currently a student pilot and have done this process many times.
My parents are both pilots. The numbers are just my estimates from having flown with them a bunch. Maybe my numbers are a little high, but I think I'd stand by them.
There's always a bunch of dealing with cranking open the hanger door with the winch, dragging the plane out, checking that there is no water in the fuel (both tanks), transferring the stuff you're bringing with you from the car to the plane, getting into the seatbelt, plugging in the headsets and checking that they're all working, talking to the tower, taxiing out to the runway, waiting for a plane or two to take off, and then actually taking off.
