Why does classical music sound so much better in vintage/historic recording?

That's too old. Peak recordings are from around 1950s to 1980s. It's not just better because of the warmer analogue sound and distortion, but because the performers were much better and individualistic too.

Music is all about nostalgia, a timecapsule evoking a certain time and place, even when it is evoking the current year. Classical attracts a lot of people who want to be nostalgic for an era they never even experienced, back in the good old days when there was real music, people knew their place etc. The presentation is a big part of that, scratchy old windup gramophone recordings, low resolution sound puts them back in that era, even if people then didn't hear the sound like that. Same way black and white or sepia photos seem classier or more in tune with the times, even if people weren't colourblind back then.

Because the frequency is closer to the more natural 432hz humans long for