The quality nosedived when folks no longer needed a recording studio!
Now anyone can buy a laptop and some software and record an album. No training or skill needed. No concept of accoustics or mastering required. A lot of artists now record their major albums on the road in their hotel rooms with a Macbook for Christs sake.
Twenty years ago the young tykes would have been pushed into a well equiped studio and issued with a couple of experienced engineers and a producer that knew what he was doing and kept them from touching the desk.
Listen to those pop albums from the 80's and they sound fantastic. Even what we considered the throw-away pop from the 70's and 80's sounds like a David Sylvian sonic masterpiece in comparison to the pop of today.
Dynamics, space, layering of vocals and instruments, placement, studio tricks, they are all there in those vintage recordings but totally absent from 90% of todays pop/rock.
To frighten the kids of today and let them know what dynamics mean I sit them down and play them Scot Walker's Tilt. They nearly hit the roof when one part in particular plays. Here endedth the lesson.