This would stop the currently exponential pace of growth from outpacing what society, and regulation, can adapt to. Thus avoiding the inevitable crash that will happen when we lose control of the exponentially accelerating train of technology, and it flies off the rails.
Governors don’t cut off supply of steam - or fuel or anything - in a on/off kind of way: they regulate the input flow continuously in a way that self-stabilizes at the desired engine speed.
Good catch, fixed