From the July AOPA Flight Training magazinem by Jason Catanzarti:
My Dad soloed in 5.2 hours in 1946. Sulley Sullenberg soloed in 7.6 hours in 1967.
So just learing to fly a basic around the pattern and land is not hard. Getting the private license of course involves more.
He says he beleives anyone with basic intellligence can learn to fly an airplane.
So what has changed over the years? Not necessaryily the planes, the ariticle doen't say type, but Sulley may have well flown a C150 or 172 back then, same as a student now.
What has changed is that while learning to fly was not unusual back then , that for many people now they think it is unusual and therefore must be hard.
If the CFIs can get folks to take that first intro lesson and they have fun doing it, they may well come back.
That is of course if they have the money and the time and sadly with all the airports that have closed and all the flight schools that have moved away from the big population areas,if the student still has ready access to flight training.