We got Rock and Roll instead.

In the BTTF timeline, Marty goes back to the 50s and very publicly defeats a group of bullies with the power of skateboards.

Marty then goes to the high school dance and plays an aggressively mediocre version of a Chuck Berry classic.

These two events warped the priorities of that universe. Skateboards became the next big thing and led to the creation of hoverboards, while Rock n Roll languished.