Honestly Whitebeard was for me , he got world strongest title and at that time I was thinking he was probably a tier above almost anyone .
Yet he failed for me , first I saw him clashing equally with Shanks , all that hype just to tie with much smaller guy I was thinking , same guy that lost a arm at first volume.
Then Marineford came and I expected him to wreck some admirals, not all at once of course but didnt expect him failing to do something to Aokiji and Kizaru . He fought Akainu yes he did manage to overpower him quickly but damage he suffered for that made sure he is not leaving war alive.
Then later I kinda realised each admiral and yonko are roughly at same level.