IDK, I’m kinda torn on this one
Initially thought that GAs would be 1 per item which is perfectly fine, but then the “standard pool” of affixes is too low to have something unordinary/interesting and not be a “life per second” or LPH meme affix 
But then I think gives Uniques the final value in return (4GA Uber/Mythic uniques >> 3GA Tempered Legendary, or at least seems to me)
And yes, as the other guys said - it is a problem if 3GA stuff can be an object of massive trade/s