Only because like labor, corps also get Govt largesse.
Just like the railroads who captured Govt to regulate for them, (by their own industry appointees), such that barriers to entry got erected for the upstart competitors who were nipping at their heels profit wise, where now kept at bay. The upstarts who were risking their own capital versus the taxpayer's, never foolishly invested "free" money that they, unlike the bigs, never had. The malinvestments and complacency of the Bigs, operating with lots of OPM, is exactly why the upstarts WERE more competitive and had to be quashed for the cost of campaign contributions.
That's what was wrong with the phone company for decades as well. The AT&T monopoly was created by the government.