The state of US domestic airlines is squarely a market result. People have shown time and again that 95% of their purchase decision is based on price, and airlines have been trying to take prices lower and lower. This is what gives us Basic Economy fares.
Fees for bags are here because AA realized that people would pay them - and the other airlines quickly piled on. This is why we should be encouraging competition and breaking up the mega-three oligopoly.