Sure. Lots of info about the Taino, for example:
https://en.wikipedia.org/wiki/Ta%C3%ADno#Culture
http://www.latinamericanstudies.org/taino/taino-conquest.htm
"Although a peaceful people, the Taino did not simply sit around waiting for the Spaniards to bring about their destruction."...

If you don't believe in the 'noble savage', please read about Tecumseh. He was a great man.

As an Englishman, I know for certain that life on these isles has degraded in every important way for many hundreds of years. Where I live was where the last free hunter-gatherers lived in Britain until the 17thC when they too were genocided.

They had short life expectancy, no modern amenities, and they were generally very ignorant of the world around them.

That's not correct. In many ways they were far superior to us. They lived longer, healthier lives, and understood reality far better than most westerners did, or do today.
Look at vids of modern-day hunter gatherers - e.g. in the Amazon, and see how at 60+years old they look about 40, and are still climbing trees for hours hunting monkeys.
I saw one vid, with an 80 year old, and he looked about 50.

We're taught at school, and by the media, that this is the best culture that's ever existed. Right? Do you think they may be hiding something?

This year, in England, we can expect perhaps 20,000-40,000 people to die of cold in the winter. These people don't have 'modern amenities'! Native people would never let their old folks die of cold!
(Last years 2015:)
http://www.telegraph.co.uk/news/weather/11382808/Winter-death-toll-to-exceed-40000.html