CLEAR is a garbage program (it adds zero value to the process - the bottleneck / throughput limiter for security is not identification, it is the actual security screening process - it is just an inefficient "line-skip" program that could be done just as easily without needlessly collecting people's biometrics).
That said, at some airports, it actually helps because most people don't have it so the line skip effect matters.
In Atlanta, it doesn't even help because half of Atlanta is Diamond (obviously a massive exaggeration but you get what I'm saying) and Diamonds get it for free. So the CLEAR line is rarely better than the regular line (either the regular SkyPriority line or regular Pre-Check line if Orwellian programs are your thing).