We were all in the beginning stages with the cars and no one really knew anything. Some, like Jim Bell, did not know anything but they knew how to market and sold more snake oil than was ever sold off a horse and wagon.
There are still guys out there that mix a little science with aggressive marketing. Joe Blow brought his car in and left with one that should make 600 hp on a Dyno...modern day Tik Tok marketing.
In the meantime, there HAS been some major league improves in turbos and converters as well as fuel management if one truly needs it.
Or one can just LS swap and forget about magic lol