You kinda miss my point a little. What changes stuff in our world is rampant capitalism (the invisible hand?). Legislators are like those rodeo dudes trying to stay on board. With or without a step change to pilot training (which I completely agree is a massive ask), them old aircraft will continue to fly only as long as the market driven aviation industry allows them to. Likewise their replacements will only continue to be produced economically in a functioning market. I merely mention pilot training because the way it is conducted now distorts the market in GA's favor. Were that to go the fallout for GA would be catastrophic, but again, probably not going to happen.
Nevertheless, fifty years is a heck of a long time. My guess is within half that time, the GA industry (and by that I mean private recreational low cost flying) will have taken some pretty brutal hits.