I presume they are referring to the airline deregulation act of 1978. There used to be dozens of regional airlines whereas now we notably have 3-4 giant corporations after decades of aggressive mergers and acquisitions.

https://airandspace.si.edu/stories/editorial/airline-deregul...

You’d be surprised but there are still regional airlines. This is because a company like delta franchises some routes basically. You might go on a delta flight and ride on a delta plane, but the operating company is some almost unheard of regional one.

In many cases that's just to skirt around various regulations and union contracts.

I’d guess also you wouldn't have to handle the maintenance end of these smaller planes eg. your bombardiers and what have you if you’ve spun off all those flights

>I see a handful of identical mega corps with a government protected monopoly (regulations + access to airports)

I see the opposite: new, brightly-colored airlines seem to pop up every year, each offering substantially the same thing: sub-$100 direct tickets to Florida (and probably other) destinations from low- and mid-tier airports. And they're all catering to the people who these rewards programs are shedding.

GP is referring to the deregulation of the late 1970s. Before that, there were a large number of smaller regional airlines in the US, that have since mostly disappeared.

I feel that's not specific to airlines however. Car manufacturers, groceries, white goods, etc.

Big companies have just figured out that scale and vertical integration kills everyone smaller.

They didn’t figure it out. Technology enabled it.

No one figured it out, it's the logical end result of capitalism.