Show of hands: who is actually a fan of this system? Does anyone remember what it was like in 2E? I think 3E keeps the exact worst aspects of those rules: where different races were better at different things to the extent that some races couldn't take levels in a class AT ALL, and the way multiclassing worked for humans and "demi-humans" (everyone else) was actually night and day. In 3E, at least, everyone is ostensibly on even footing: dwarves and elves have the same max level for Fighter, for example, and no one is restricted from taking levels in Bard or Sorcerer, even if they would not be particularly good at it. But there is this weirdly arbitrary clause that states everyone has to keep their progression in different classes on an even footing or they start to accrue experience point penalties, but one class (the one they are biologically or culturally predisposed to excel in) is exempt.
But that isn't the way learning things works in real life. How much you know about particle physics has no bearing on how easy or hard it is to learn how to cook, no matter how long you've been studying either. A postal worker who decides after 15 years to start training to be a librarian isn't any worse off in that endeavor than if he or she had started on Day 1 in both jobs and worked from the ground up at the same time.