Yes, it is. Would you trade places with them? Would you want your children to?
We have huge wealth and health disparity
Which we could certainly eliminate by destroying all our wealth and abandoning medicine. The only thing that should tell you is that "inequality" is a poor metric.
And none of this implies that it would be acceptable to forcibly impose our civilization on anyone. It does imply that we should offer them the choice.
However, we are a stressed out, overworked, sick society who has lost traditions such as appreciation of family, and our idea of relaxation and "living life" is a 2 week vacation once a year. Sure, we've got great tools and Xboxes and the Internet and modern medicine... but at the end of the day, 100+ million Americans are literally sick (defined by the prescribed medications that over 1 in 3 have to treat symptoms of sickness).
If I had grown up in their tribe, and was given an opportunity to completely understand the pros and cons of the new society, I may just want to stay ignorant in my tribe.
It's quite possible that while they're likely less intelligent, less advanced and very primitive, but happy and connected with each other and have a quality of life that comparatively (to them) is better than our way of life.
At the end of the day, to me at least, quality of life is what's really important. To others, it's competition, satisfaction of proving that they are better than others, money, and egocentric activities that make them happy (and that's fine).
Honestly, I don't know how did you get so many upvotes. I mean, we have this huge imbalance problem of equality between different peoples right now, which could be easily solved if only the "superior" whites in Europe and the United States would vote down the anti-immigration rules.
The situation of poor sub-saharan people, whose way of life was irremediably "improved" by superior European colonialism, would very much be improved if they were allowed to travel and work freely in all over of Western Europe. The same goes for the United States and its hinterland in Latin America.
And let me tell you what would happen were we to contact these tribes. Half of them will die from a disease like normal influenza, while the rest will be either lost to cronic alcoholism or to the Brazilian favellas. We've seen all this happen before.
For instance, it's said that 99% of Japanese who attempt living abroad end up returning to Japan. Is it because their way of life is "superior"? The vast majority of foreigners who try living there end up returning from where they came from, as well. Is it because we're all superior to each other?