There are tons of airlines. I can often have my choice of airlines to fly to a particular city, nonstop, within a given hour. Where's the lack of choice? Economy tickets range from cheap to very cheap, unless you need to fly somewhere like Guam. Renting cars and booking places to stay are both significantly more expensive pieces of traveling. As long as that's true, it's hard to justify flights getting that much cheaper... unless you're flying a family of 6+, in which cases you're part of a small market.
There are tons of airlines. I can often have my choice of airlines to fly to a particular city, nonstop, within a given hour. Where's the lack of choice? Economy tickets range from cheap to very cheap, unless you need to fly somewhere like Guam. Renting cars and booking places to stay are both significantly more expensive pieces of traveling. As long as that's true, it's hard to justify flights getting that much cheaper... unless you're flying a family of 6+, in which cases you're part of a small market.