Who decides what is important? Who decides that steel is more important than small farms is more important than cryptocurrency? What are the metrics to decide "important" and how do we avoid this just becoming another subsidy to funnel money to cronies in your home state?

Does the government then get to set the winners and losers across broad swaths of industry?

Yes, the government does. Things can go very wrong with the state and the market. I have no patience for one's fears entirely being over one not the other.

Yes, we have endemic regulatory capture. Yes, we have shitty voting systems that severely restrict the electoral options and, worse, the Overton window.

But also, study the WW2 build-up. This was heavy state managed and did a fantastic job, and certainly our voting system were no better then.

I also hope a combination of UBI and Carbon taxes can work — so the relative prices of things change but the overall cost of living doesn't go up.

But a very easy to understand example of where that is insufficient is that it will be much more efficient to build out public transit than try to make electric cars for everyone cheap.

The structure of the US healthcare system is a direct consequence of how the government managed the WW2 build-up. Many people would assert that this was an extraordinarily damaging adverse outcome of "state management" that still causes very expensive and enormous problems going on a century later.

The history of state management is rife with adverse unintended consequences due to rampant short-sighted application of state power.

UBI and carbon taxes synergize in making your country woefully uncompetitive with other nations in international trade, fwiw.

Well, the relatively closed countries need to lead the way, enforcing tariffs on countries that don't comply.

As with most things in economics, "demand comes first", so the big importers need to lead the way.