Don't know about the first part of your question as terrible things happen every day somewhere. As to the 2nd bit about decades that didn't last 10 years I'm pretty sure we can say no to that
The song you linked I vaguely remember it from a movie. I love early 80's post punk synth pop new wave whatever you want to call it. Never heard of this band.
https://www.youtube.com/watch?v=rtztb_AwuCc great American folk/punk band, you probably heard of them.
You mean has there been a full ten years during which some portion of the billions of humans on Earth did not have an extended go at killing one another?
Probably not since thousands of years ago. But that's not a product of our society becoming more violent, it's a product of it becoming larger.
I would say that the 1920s before the depression and after the world war was kind of a cool time for america...
A lot of the names from the 70s were still very active in the 80s as well.
Notable acts were:
Led Zeppelin, AC/DC, Journey, Rush, Rainbow, Jethro Tull, Genesis, Ozzy, Stevie Ray Vaughn, ZZ Top, Tom Petty, Fleetwood Mac, David Bowie, Roxy Music, Talking Heads, R.E.M., YES, Peter Gabriel, Kate Bush, Thin Lizzy... Just to name a few...
And in the pop camp....
Michael Jackson and Madonna need mentioning.
And then the army of New Wave artists.
Songwriters cranked out truly milestone albums:
Lou Reed, Leonard Cohen, Paul Simon, Bob Dylan.
Nope, there was no shortage on quality at all.
"The pen is mightier than the sword.. and considerably easier to write with."