Exactly - the FCC certification is that a specific device, despite having purposeful (or accidental) transmitters, operates within the law and rules set by it f

Exactly - the FCC certification is that a specific device, despite having purposeful (or accidental) transmitters, operates within the law and rules set by it for use of radio spectrum. The maker of the device is then able to sell it to people who are then indemnified should the device break those rules (and aren't required to have expensive in time and effort radio license themselves). With significant portion of the regulated behaviour being done in software, things can become a bit problematic if the end user can load any code they want. This is also why "BIOS whitelists" exist, as the certification applies to the whole radio equipment, which means the certification must cover the antenna - and those are built into laptops, meaning you can't certify the cards separately as their exact characteristics depend on the connected antennas.