Genre conventions can be limiting, although there's so many bands that perfectly fit them or a mix of a few, that they're quite useful. But it's actually also useful to the people making something unique. When carefully listening they now perfectly know which boundaries they can play with to create something unique. They know exactly what's uncommon in certain genres. Sometimes people create something unique by playing in a genre they know little to nothing about, as then you go in with a totally clean approach.

Genres are also useful in finding the sound you want to create. Maybe take the tensity from one, with the beauty of another. The result doesn't even have to sound like a mix of the two, but they did help finding said sound.

Lastly, there's stuff that's unique by complete accident.

It all starts to be a problem when

a: They play a lot of different genres, and none is the majority.

People will start to get confused under what to categorize it under, and sadly this means its harder for the artist to reach it's niche and get recognized.

b: They're difficult to define at all.

Once again this makes it hard to reach the niche it needs to get recognized. Especially if it gets put under a genre that belongs to a niche that would hate the sound. In this case genres tends to hinder creativity. Instead of just making whatever the fuck you want to make, one might try their best to fit into the boundaries of the genre they want to be in. Which isn't ideal, let's let people make whatever the fuck they want to make and not worry too much about the label.

I agree that focusing on the ''sound'' instead of a genre is a great thing when creating music. Some sounds are instantly recognizable, but quite hard to put under a label. Is that a bad thing though? It just shows how unique and recognizable said artist's sound is. Different approaches are always nice to see too.