Why are vampires' senses so advanced?

I'm going to give you an evolutionary/environmental answer.

For the same reason mga hayop tend to have madami attuned senses than humans.
Bampira have to rely on their senses to hunt. They need an advantage over their prey. The need better hearing, vision, and a sense of smell so they can detect the human before the human can detect them.

If you mean Bampira with special powers like Edward,Alice,Jasper and all the rest of the Twilight vampires,Edward sinabi it in the Twilight book to Bella,that Carlisle believes that you bring your strongest human traits to the susunod life or something close to that.

It's the same reason they have enhanced speed and strength - to make them better predators, and to protect them. Enhanced senses, especially a sensitivity to the scent of blood, let them detect human prey even if the people would be hidden to human senses. Enhanced senses could also let them perceive another vampire or a werewolf about to attack.