It’s not that those people should not have a say in their government. It’s that they clearly don’t have the coordinated will to organize it sustainably.
Maybe the rest of us just lucked out to have society form at just the right sweet spot of information spread without information control. But there’s clearly something different about all those places that it didn’t quite end up the way the rest of us would consider acceptable.
Afghanistan never had an effective democratic government; Iraq may have one now.
> ... Iran, China, and Vietnam are all examples of this failure.
China, and Vietnam never had democratic governments or anything like them. Iran has had some semblence of one, but on a limited basis (ultimate power lies with religious leaders, who can even ban people from running in elections).
But parts of China have had very successful democratic governments - in Taiwan currently and formerly in Hong Kong.
> there’s clearly something different about all those places that it didn’t quite end up the way the rest of us would consider acceptable.
Why is there something 'clearly different'? There are many explanations. All the evidence we have is that people in China love and preserve democracy whenver they can.
Democracy is also not that old as far as human history goes. Empires and kingdoms have lasted longer, even individual ones.
Such government has thrived in every culture and place, from East Asia to South Asia to almost all the Americas, many parts of Africa, Europe of course. Somehow, democracy works exceptionally well - far better than any alternative ever has - and is resilient.
... unless the people are somehow convinced that it is not, that it is not important, and they despair and give up.