Which could be done even cheaper by the like of Broncos or Super Tucanos or Reaper drones. So why shouldn't it be replaced by Tucanos and Reapers and 35s?
The F-35 lacks the loiter time and payload capacity that an A-10 brings to the CAS mission. While I have no data, my understanding of aerodynamics and thermo suggest that F-35s do not have terribly good performance or handling at low altitudes and speeds. While can't speak to the F-35's ruggedness, it's a damn expensive airplane, and patching bullet holes AND maintaining stealth has got to be expensive.
I don't know enough about the Broncos or Super Tucanos to say much. Reapers are optimized for high, slow, long flights. Those long thin wings are not so great for aggressive maneuvers, like pulling a tight turn for a second attack run. They are also more susceptible weather, both aerodynamically and from a telecommunications perspective.
And while many of us are not, as you say, experts, I suspect that most people on this thread are aviation buffs and know quite a bit more than the average person. :-)