Of course I respect your opinion, but I object to "it is just adding complexity for the sake of itself"
Hierarchies are very useful if implemented correctly, and life would be much harder without them.
Country > City > Street
Animal > Cat > Siamese
Clothing > Underwear > Bra
My proposal is nothing more than factual, and when implemented correctly I can only see advantages.
But to add to the quality of this proposal, of course feel free to present factual drawbacks.
Terms as 'difficult' or 'complicating' would be too vague in my opinion.
Just compare these two examples. Same genres and subgenres.
I think it's hard to argue looking at those?

PS,
I would agree with you if the purpose was solely to play 'archiver' or 'stamp collector' with too much time on hand.
The purpose though is to find, discover and play the music that you want to hear much more easy.