Ok, i'll explain:
Thor has far more impresive strength feats (on average).
Thor has for more impressive durability feats (on average).
Thor has better speed feats, of which diana only really has one good one which is PIS at its worst when placed next to her other speedfeats (zoom fight).
Neither of them are nearly as skilled as people would have you believe.
Diana has basically zero wins against other top tiers. Her best showings are against a daxamite who was freshly under a yellow sun (supes beat 3) & a white martian who have at other times beaten her solo.
Diana is below the accepted top tier bracket. She is as close to thor as the Thing is to her in a brawl. She can put up a good fight but she wont be in too much danger of winning.