Chicago school assholes backed by economic-right postwar "think tanks" managed to radically shift our standard for "harm" in anti trust enforcement, back in the '70s, though a combo of lobbying and positioning their folks in the right places. The result was that it became nearly impossible to take anti-trust action. That's why it seems like we suddenly stopped enforcing it—we did. This was followed shortly by a shift way to the right by Democrats on economic issues (among other things—listen to Clinton in the '90s talk about crime or schools or lots of other topics some time, he sounds exactly like a Republican) after Reagan's landslide, which put any hope of reversing that bad course on hold indefinitely.
The first notable push-back on that state of affairs was Lina Khan under Biden, who ever so slightly course-corrected us back toward healthy market competition in the tiniest of ways, and every business bro reacted like she was committing mass murder. Meanwhile, we need that times ten for at least a decade just to get us back to something resembling functioning markets. At this point I doubt we'll see a shift back toward reasonable market regulation... ever. Plutocrat capture of the levers of power is so complete that the only way I expect the US to see serious anti-trust action ever again is as a tool of corruption.
The first notable push-back on that state of affairs was Lina Khan under Biden, who ever so slightly course-corrected us back toward healthy market competition in the tiniest of ways, and every business bro reacted like she was committing mass murder. Meanwhile, we need that times ten for at least a decade just to get us back to something resembling functioning markets. At this point I doubt we'll see a shift back toward reasonable market regulation... ever. Plutocrat capture of the levers of power is so complete that the only way I expect the US to see serious anti-trust action ever again is as a tool of corruption.