Gary, I will say, even in these parts there are a lot of people with older cars who don't work on them, and certainly many who won't open up a carb.
This isn't limited to carburetors as you noted, when I was running Relentless Performance there was a sizable number of people who would just throw a car together and declare it done.
Tweaking the cam timing, distributor timing, fuel pressure, injector size, etc, etc was a concept they could or would not embrace.
In my experience that's where the real gains are, honing the car till it runs its best. At the other end of the spectrum, I attended a dyno event in Ohio where I worked on a guys calibration and made over 30 pulls!
There was literately nothing left on the table when we were done.
