Ab has been extremely consistent in recent years too. It's just that he's consistently getting 60s and Smith has been getting 150sABdV batting at his best is definitely a cut above Smith's best. Smith's strength is more his sheer consistency.
I don't think the difference between ab and Smith is as big as we have been thinking though. AB has been making incredibly challenging runs and his 60s are matchwinning about as often as Smith's 150s are.