... you've not been recording metal bands obviously.
Call me lucky.
The last Metallica album sounded like pure shit...audio-wise.
Just a lot of harsh noise...because everything was pushed to the absolute max. BUZZZZZZZZZZZZZZZZZZZZZZZZZZZ
But I'm not looking to crack on Metal *music*...
...I just find it rather amusing that Metal has reduced itself to a very calculated *process*, which you refer to as "mandatory perfection".
Guys punching in single notes for their leads, drummers tracking fills one at a time and using triggers of "perfect" samples instead of their drums...etc...etc...etc.
I didn't use to be that way...and it had nothing to do with those earlier bands being "sloppy". Metal came about as an alternative to the formulaic MOR "Rock/Pop"...and now it's more formulaic than some current Rock/Pop music.
These days, a lot of Metal to me is very much like the WWF....just a theatrical show, with costumes, lighting and pyro FX and lots of glitz (though Metal just goes for the "dark" look instead) .
But I guess if that's what people want to see...then it has its place, like any other kind of music/entertainment.
I use to like Metal through the late 70s and early 80s.
YMMV