If you want to overbook like crazy and bump passengers off the plane, you should be free to try that. It's a free market, and no one is forced to fly with you.
Commercial aviation? Good one. When’s the next bailout?
In any case, have the budget carriers ever gotten a bailout?
If I call up an airline and ask them: what happens when you bump me off, and they say they will find me a new flight immediately.
In practice they often dont wven pick up the phone because they don't have enough staff.
And they get away with this
Those tools are applicable in many situations. Eg when Amazon doesn't send you the stuff they promised. Or when your shoeshop sells you knock-off Prada etc. It's a common problem with standard solutions.
Those standard solutions apply (or should apply) to airlines as well.
Eg when the airline gives you less legroom than they promised etc.
Furthermore, a flight might be cancelled for any number of legitimate reasons (weather, strike, technical problems, crew limitations, change in government rules, etc.). A flight is not like a car trip (even though the aviation industry has been so spectacularly successful in delivering safe and reliable flights that people often forget that).
It is foolish, in my view, to rely on making any given flight.