The short answer is this: They held an official player poll, and the majority wanted physical levels gone because it was cumbersome and unnecessary.

Also, skill = experience.

If I have experienced at using something, can I not say I'm skillful with it? I'm not being snarky or sarcastic... I literally do not understand the terminology issue.

Skill: the ability, coming from one's knowledge, practice, aptitude, etc., to do something well: Carpentry was one of his many skills.

Experienced: 1. wise or skillful in a particular field through experience: an experienced teacher.
2.having learned through experience; taught by experience: experienced through adversity.