Wolf's Bane wrote:
1. What do the rankings matter? Does the entry standard not trump world rankings?
3. Time standard always trumps world rankings right?
The combination of ranking and extremely high entry standards is a (maybe foul) compromise. So yes, for now the standards trump the ranking but the idea was exactly the other way round, namely to have ONLY the rankings and not standards as qualification method.
Because the number of athletes had to be restricted. With the normal standards of former times, sometimes so many got the standard that the fields became "crowded" (compared to other sports). The IOC put pressure on the IAAF to reduce the fields. And Coe etc. have some other spurious reasons why they love the ranking system (e.g. the DL gets you very high scores). There are even some good reasons for a ranking system, e.g. that athletes have to perform frequently at big public meets. Not throw 77 meters hammer somewhere in Kazakhstan exactly once, get to the Olympics and flounder there with 69 m. Or hide in Ethopia, show up only for the Olympics and run a fabulous 10k WR.