Genre is dead, and what we now call aesthetic is basically the new genre. Sad girl aesthetic: now that's a genre of music.
Aesthetics can cross traditional genre lines but unite things along visual and sound information. They can provide more information than the genres we've known while blurring existing genre lines. It allows people to say, "I don't belong to traditional genres," while clearly there's something new that does categorize them.
Lofi: that sounds like a genre, it's also basically an aesthetic. Yacht rock, that's named like a genre, like punk rock.