Tweetwow! The Eagles, AC/DC...well, every one you listed has been in the studio. Might be impressive. Usually it's just not. I think the reason so many music entertainers only have a couple great albums at first is because what was great about them, and their style, lyrically etc...is they produced the great stuff while they were still on the down side of things. Not really "down", but they hadn't yet received star treatment from everyone and became very wealthy. So that change in lifestyle, having their ass wiped for them if needed, and new found wealth, changes the person's personality, and complete way of thinking. Hence the shyt music later. Never putting anything out worth listening to after their "sophmore" album.
Then you have groups like Aerosmith, Metallica, The Beatles...that continued to put out good stuff well past their 1st & 2nd albums. They literally "keep it real". Somehow holding on to that raw ingredient that made them, while getting better as they graduate.
I remember my uncle saying "that's it for them", when Kiss busted out with the Beth ballad.
It's something to listen to Kiss and think "heavy metal" after metal actually got heavy. They're not far from Foreigner.lol...
I know everything that you listed would take me back though. It's something how music has the ability to move you to a time and place...it can put you right back in that moment.