> There are plenty of disastrous decisions in the last 70 years at the level of major policies. There are plenty of failed projects.

Failures are everywhere, even the OP acknowledged that. I think the more important question is what a system does with those failures and how well it can learn from them and improve. (And if course, what does "improve" even mean? What are the targets that the system optimizes for?)

So my question would be, could China learn from those failed projects and improve its policies? How many disastrous decisions were there in the last 5 years in contrast to 70 years ago?