There is one way that I know of wherein "spotlight balance" is achievable while playing D&D, and what classes are being used has nothing to do with it. Unfortunately... most players don't play their RPGs in this way so they don't get to experience it.
Talking in character most of the time and focusing on story.
When story and characterization is the primary focus of gameplay-- the players saying what they want their PCs to do and speaking with NPCs the DM controls (negotiation, exploration, argument, planning, invention, etc)-- then the spotlight all becomes about how often people step up to talk and what it is they they wish to say. And if you want to throw some ability checks in there too just to get some mechanics into the game, that's fine too.
But this is exactly how the "weapon-using characters" get to easily be in the "spotlight"-- contribute to the game all the time and at much greater levels, oftentimes more than the "magic-users" can do. Because everyone can come up with ideas and talk about them, and it doesn't matter what your class is or what game mechanics you have at your fingertips when you do so. When the group needs to accomplish something, then the Fighter player can come up with the idea and solution and present it to the team and get the "spotlight" on their discovery... even if the solution is for the "Wizard character" to use their X, Y, or Z spells in somesuch way to accomplish it.
Now sure... the mechanically-focused tables will say "No! If the Wizard is the one who uses their spell mechanics to cast the spell to solve the problem, then they are the ones who got the spotlight!" (even though the Fighter player is the one who actually thought of the idea and had control the of the table as they worked it out and presented it to the group). And if some people play at tables like that... when only the use of the numbers on a character sheet count as "spotlight time"... then my point is going to be a poor one for them. But that's fine. My style and focus of playing RPGs is an exceedingly small minority and we've all known that for decades. But if "spotlight balance" is really such an important thing for some players... then changing their game's focus to be about characterization and talking in character and improvising discussion and such is a great way to do that while still being able to play D&D (if changing your game away from it to one with more mechanical spotlight balance isn't going to fly.)