It used to be possible to bust up a company based (more or less) simply on their having too much of the market.

Right wing interests built up think-tanks after the Second World War, having seen the success of especially the Brookings Institution during the New Deal and world war eras in pushing technocratic-liberalism and wanting to fight fire with fire by creating their own credibility-laundering offices for propaganda advancing the desires of the rich. This effort bore its first great fruit in the mid '70s as Chicago School economists and lobbyists successfully overthrew that enforcement regime and replaced it with one in which specific harm must be proven to win an antitrust case, which de facto ended meaningful anti-trust enforcement in the US and led to the consolidation of money, power, and media over the following decades.

Aaaand... here we are, in the endgame of that movement.