Too much oversampling why?

Anyone knows why there is so much oversampling?

I mean recording did oversampling, streamer take the master polish it so there are all at same level of db when playing and oversampling it and then you stream at another oversampling, your machine took it and then oversampling it to play? Why?

could the master could be the original in NOS, than because random listening need all music play at the same db level, if not, your ear will explode on some playback (I know, it is not really the original your are listening, it is a polished version you are listening).

So remember at the office when listening the radio, no rock song is anoying, but at home, sometimes it was. It was because radio were polishing the result all sound same level and troncate some annoying sound in music.

But back to track one, why so many oversampling:

Musician; Studio; Mastering; streaming and home listening mastering.

Why we could not stream direct music without oversampling directly to end user, who decide what oversampling it need or not and then transfert it to analogue.

With all that oversampling (lot of bandwidth for all the extra data…!), are we really listening HiFi like HiRes CD or even vinyl sound?

please explain?