At least in the US, there is a very reasonable argument that the administrative agencies have overstepped.
As an example, from the FTC:
"Unfair methods of competition, the policy statement explains, are tactics that seek to gain an advantage while avoiding competing on the merits, and that tend to reduce competition in the market".
Who decides what "the merits" are, and who decides what the "market" is? They play a lot of games with these definitions. What are the merits in the smartphone business? Did apple abuse their position to unfairly take over the camera business? Is "cameras" even a market anymore? Is a camera so clearly part of a smartphone that it does indeed meet the definition of "merits"? Is Amazon abusing their position in e-commerce to take out the delivery business (fedex etc) by offering "free shipping" ? Is AWS abusing their position in IaaS to unfairly compete in the "server cpu" market? Is that even a market? Or is it not because x86 chips and ARM chips are thought of as different? Read the current case brought against Meta. The definition of "market" is... really pretty awful. Someone is just trying to make their career.
Only if you ignore most of the text of the congressional acts that have created them. If the FTC's charter consisted of that one paragraph, it would be a reasonable criticism. It doesn't, and it's not.
It's true that there's a reactionary movement in the current SCOTUS that comes up with very odd interpretations of these congressional acts (like concluding that CO2 is not a pollutant, and thereby can't be regulated as one), but just because Amy Coney legislates from the bench that the sky is green doesn't necessarily make it so.