At birth there are situations that give people advantages that have nothing to do with ability. These advantages are systemic, where certain people will have better access to opportunity (apples) than others. The goal should be that the opportunities are equal so no one has a head start. The best apple picker will pick more apples instead of the person born with an orchard and apple picking machinery who very well may be a shit apple picker.

For your example, we’d end up with the best musicians becoming popular, not the ones where their parent could afford to give them private lessons since childhood and had industry connections to make them big where they wouldn’t otherwise.

It’s not about equality of outcomes, it’s about equality of opportunity. No one should start a race with a head start because then you don’t know who the best runner is. Everyone should start equally and everyone should have equal access to the same shoes, equipment, and practice opportunity, otherwise we can’t see who’s actually best without an advantage.