It hasn’t been common recently, under Obama/Trump. The Biden Admin FTC seems like it’s serious about using antitrust laws to prevent the market from being too lopsided in favor of a few big players.
More like Bush II/Obama/Trump. The FTC has been neutered for a while, particularly when the rulings about decreased competition vs consumer choice were made in the mid-2000s.
The reason for competition law is to regulate the free market to ensure that consumer choice is not limited by the uncontrolled acquisition and merger of suppliers.
The merger of NVidia and ARM is inherently non-competitive unless NVidia accepted limitations/restrictions on their licensing freedom which they are not willing to propose or accept.
That's leaving aside the international and other ramifications of a company that is involved in the entire vertical of chip production and sale through to retail having control of the licensing of the most used ISA and other IPRs that are available to its competitors throughout that vertical.
