Comparing opponents isn't that meaningful. If it were, Miami would never have won all those titles back in the day because it is difficult to find schedules weaker than their independent/Big East ones. The same thing could have been said about FSU in the ACC, Florida when the SEC wasn't as nearly as good as it was until recently, USC in the nearly always joke Pac-10, and I will go ahead and say Nebraska and Oklahoma in the Big 8, or should I say Big 2 and Little 6 as it was often called, with Colorado becoming good only when Oklahoma got hammered by the NCAA.
Instead, what is meaningful is talent. The frauds who pile up on weak competition only to get exposed are generally those that aren't that talented. That isn't the case with either Oklahoma or UGA. For example, Oklahoma appears to have the best OL in the country, one that will send several guys to the NFL over the next 2 years. UGA's front 7? More of the same. Thanks to the massive injuries to Alabama, it is the best in the country - Clemson and Auburn have the best DLs, but UGA has the best DL/LB combination - that will also send several guys to the NFL this year and next.
Also, Oklahoma has the Heisman winner at QB. UGA has two future NFL starters at RB. The fact that UGA was the only team in the SEC East to win more than 8 games doesn't negate Chubb and Michel's talent no more than the "defenses" at Oklahoma State, Texas and for my money Ohio State (see what Penn State did to them for the first 3 quarters) take anything away from Mayfield.
I personally think that this is going to be one of the best games the playoff has ever had, maybe rivaling Clemson/Alabama last year. It might even be better, as Oklahoma/UGA has an even bigger contrast in styles than Clemson/Alabama did.