I don't know if music was "better" back then.
I do think that nostalgia tends to look at the truth through rose-coloured glasses.
A lot of the music we love is connected to certain feelings and experiences. And you're feeling and experiencing a lot of things during puberty and your early adulthood. I think that's why it seems like a lot of people's favorite music of their lives seems to come from that era of their lives.
For me was the early 90s to the early 2000s. Though I really identify with a lot of late 70s and early 80s Punk/Post-punk.
I mean if you're 35, chances are you don't really hold up the Drakes and Taylor Swifts right up there with your Nirvanas and Alanis Morrisettes.
And if you're 45, you probably preferred Madonna and Michael Jackson to Nirvana and Alanis Morisette. Or something like that.