Doesn't it depend on the sport?
The sports that are "true" Olympic events ... eg track and field ...
... being Olympic champion is the ultimate.
No number of world championships could ever match the glory of being the Olympic 400m Gold Medal winner.
But, if you're a boxer, or a volleyball player, being world champion would be more important.
Personally, I don't think any sport should be in the Olympics unless an Olympic Gold is the ultimate prize. So Tennis shouldn't be in the Olympics, because most tennis players would rather win Wimbledon than win the Olympics. But a track athlete would rather win the Olympics than anything else.