Yes--- . The problem is that there are massive economies of scale and interconnection driven by trade and global markets. In turn, the large scale of the marketplace doesn't leave much room for labor or capital to not be allocated "optimally". In turn, the amount of ability any given entity (individual people, businesses, or even nation-states) have to experiment with significantly different systems is very limited.
For experiments on the smaller scale, there's a big chance they are not applicable to broader groups. And experiments on the larger scale (revolutions, massive policy changes, etc) tend to have unintended consequences and a massive body count.
We're in a stable-ish equilibrium, but it's completely unlikely we're near any kind of global optimum on material wealth, or quality of life, or any other given chosen axis.
> of cultures which seems impoverished.
This is an interesting one, too. There was a certain threshold of wealth reached just before industrialization which allowed a massive growth in cultural expression and we have wonderful things from many cultures that emerged then... that then, with global media and global trade we've been able to enrich further-- we've played off of and learned and enjoyed the riches (culinary, musical, artistic, literary, ....) thereof. But in so doing we've strip-mined this heritage and permanently weakened the nation-scale incubators of new ideas.
> One of the problems with an increasingly global culture and economic system is the erosion of diversity. If we had drastically different systems and experiences, we could try and marry the best aspects from each. Instead, we get some semi-stable equilibrium that emerged by happenchance and the only path out towards something different seems to be by some kind of central planning or massive movement-- both of which have tended to make things worse in practice because of unintended consequences and institutional inertia.
I'm not sure I fully get your paragraph (you write conceptually dense ideas) but I kinda see a globalized homogenization of cultures which seems impoverished.