Imho, Garp looked simply better against top tiers.
If you look at Akainu vs WB, before WB rage moment and cheapshot, Akainu was clean; WB never even managed to hit him and Akainu blocked both his Saijo (with hand in pockets) and his Gura Gura attacks (with a Dai Funka?):
Has never hit Aokiji or Kizaru too.