It's like in One Piece when Akuma no Mis were considered rare and now everyone and their dogs has one.
if you live in the One Piece world in some random island in one of the four Blues, of course Devil Fruits are rare to you. and Haki is definitely a word you'll never hear.
but once you set sail and aim for Grand Line, you will need some kind of power, and you will also have to compete with
others who also have powers. having Devil Fruit power is a good advantage at this point, or you might even learn to do Haki.
then you get closer to Raftel, where only the real powerful can survive. of course now almost every single person you meet has either Devil Fruit powers, Haki, or both at once.
it's actually normal of you think about it for a few minutes