CONCEPT BALANCE requires that either the flexibility of character creation or the scope of gameplay be limited. This is why lots of people advocating for concept balance focus exclusively on combat, for example: By limiting the scope of gameplay strictly to combat, they can achieve balance.
NATURALISTIC BALANCE allows for the creation of sub-par characters. Avoiding these sub-par characters requires system mastery.
SPOTLIGHT BALANCE requires the GM to actually balance the spotlight. It can also mean that player A needs to sit around and do nothing while player B struts their stuff. (The "decker problem" in Shadowrun is an extreme example of this problem. More typical is the system in which character B has about 80% the effectiveness of character A in situation X, whereas in situation Y the reverse is true.)
These problems can be mitigated in various ways, but not eliminated. They're fundamental to these types of balance.
4th Edition is heavily invested in concept balance, virtually abandoning the spotlight balance which was once the core design principle of D&D. It achieves that concept balance by both limiting the scope of gameplay (as seen in combat) and the flexibility of character creation (as seen in the skill system).
(Some may interpret that as a slam, but it's not. It's just the reality of 4th Edition's design: They traded scope and flexibility for concept balance. Whether that trade-off is worth it depends on how highly you value concept balance.)
I agree that 4E traded most of the Naturalistic Balance for a greatly increased Concept Balance (from the standpoint of prior editions).
I don't agree that they traded Spotlight Balance so much as reduced it's dependency upon the DM (conceptually redefining Spotlight Balance, if you will). The spotlight is more present in 4E (combat) than ever before due to the role system. Defenders are "sticky", controllers redefine the battlefield, leaders crank the party's efficiency to 200%, and strikers pick their desired targets and take them out. Admittedly, there is some degree of overlap, but I doubt you could find anyone complaining that their Cleric is regularly "out-leadered" by the Paladin, much less the Wizard.
In this sense, the spotlight remains but (in combat) isn't as dependent on the DM. One can (relatively) easily demonstrate this premise by building an encounter that favors one role above another. An encounter made up of only artillery role monsters behind tons of hindering terrain would probably favor Strikers while marginalizing Defenders, for example. That is why there is advice in the DMG for what types of enemy roles do and don't favor which PC role.
Spotlight balance also still exists outside of combat, though I would agree that here it is somewhat diminished in many cases (though increased in others). The rogue is still the thieving go-to-guy, for example (high Dex, and gets Stealth and Thievery skills automatically). The fighter could , via feat expenditures, improve his thieving to the point where he wouldn't be a liability to the rogue if he wants tags along on "sneaking missions". He would, of course, be trading efficiency as a fighter for this increased flexibility (the Naturalistic Balance that has been significantly diminished but not entirely eliminated). The Wizard cannot, however, render the rogue's sneaking skills meaningless with his spells. If he wants to be sneaky, he can train the skill as the Fighter did.
In the end, I would agree that a significant amount of reshuffling occurred in 4E with respect to balance, and with a particular emphasis on increasing Concept Balance. Nonetheless, and meaning no offense, I think your statement that 4E virtually abandons spotlight balance is inaccurate. It mostly just reduced the dependency of Spotlight Balance upon the DM, rendering it a more inherent part of the system than in prior incarnations.