The FAA deliberately uses "certificated" as opposed to "certified" when referring to pilots and flight instructors.
It insists that conveys a distinct and useful meaning because they don't certify pilot quality. Instead, the pilot has been issued a certificate confirming that they passed a test to a particular minimum standard. The reason for the difference is to convey that there is no assurance or guarantee that the pilot consistently and continuously meets this standard. Unlike with a "certified used car", the FAA is not going to be held responsible if your pilot crashes your plane.
Reference: I am an FAA-certificated Flight Instructor and Commercial Pilot.
Personally, it would inspire more humility about what a certificate means and my ability to consistently apply the knowledge behind it. It gives pause immediately as I consider things I could apply it to.
It insists that conveys a distinct and useful meaning because they don't certify pilot quality. Instead, the pilot has been issued a certificate confirming that they passed a test to a particular minimum standard. The reason for the difference is to convey that there is no assurance or guarantee that the pilot consistently and continuously meets this standard. Unlike with a "certified used car", the FAA is not going to be held responsible if your pilot crashes your plane.
Reference: I am an FAA-certificated Flight Instructor and Commercial Pilot.
[Edit: typo, thank you lkschubert8]