No it spotlights the GM because wotc has given us a system that assumes the GM never gives out magic items & such along with years of leading by example. Thus far it's not even hinted at that wotc considers it a problem that 5e was designed for no no magic items unless the GM starts breaking the monster math even worse by adding them. There is strong pressure in the form of monster math that pressures the gm to not give out scrolls & other magic items like in older editions.This ignores though the key final aspect of balance in 5e.... the DM. Classes aren't just about balance, they are about hooks, ways for the Dm to make the classes each feel cool and special.
Take the monk, often feels underpowered. However, if the DM makes it where speed is a big factor in certain fights, and has lots of ranged attacks where the monk can use their ability....suddenly they are looking pretty solid. A ranger that is never in nature isn't going to feel as strong as the ranger where the DM throws some nature adventures into the game. A fighter might be given a cool unique sword or something, etc.
And the same for the wizard, a good Dm is going to throw some scrolls in the game for the wizard to find, because that is part of their hook, part of what makes them feel cool and special.
The key is that the hook is there for the DM to use, now good Dms will know to use these hooks better than others, but you always want that there, that is part of good class design.