...economics of minining ... This system simply does not make any economic sense.
I believe this quote captures the substance of your post and is the point which merits discussion.
I agree generally, that the centralization of mining is a threat, in principle, albeit not in practice to date, to the security of the ledger.
I also agree, generally, that the current energy expenditure is far in excess of the need of the design goals.
I further agree, generally, that price motivates that expenditure.
Whether it makes "economic sense" is a strange question, politically and philosophically loaded. Clearly it makes sense, because you have made sense of it, explaining features of its causal structure. I think what you mean is that the gap between energy expenditure motivated by technical needs, and energy expenditure motivated by economic factors is offensive to your sensibilities. I am somewhat sympathetic to this complaint, but the market is, as we see, without sympathy.
An argument can be made that the economic value-add of the network suffices to explain all or part of the gap which offends you, and you seem to acknowledge that implicitly, but consider it inadequate to the scale of the gap. This view would gain respect, if you were to quantify it, or to offer a reasoned case as to why the value-add is less than the present energy cost.
No "hype" is required to explain a deviation of current price from some present fundamental metric. All that is required is a rational discounting of a future price estimate (which should really be in the form of a distribution).
(Aside, I observe that this discussion is off-topic, which may annoy some who frequent the thread.)
There is a link between these two points. The power demands are such that there is a limit to how much of the mining network can be located in one area or one country. When you are pulling 10-20MW you are affecting the price in the area to such an extent that doubling this will often prove difficult to make economically viable. Of course, a company can always look for sites elsewhere, but local knowledge is often key. There is a reason why KnC mines in the north of Sweden and Bitfury mines in Georgia. KnC would get ripped apart in Georgia while Bitfury understands how to do business there. On the flip side KnC knows that some of these poor counties in northern Sweden will work their asses off to get the necessary approvals and price assurances in place in order to get energy intensive industry to their county. This promotes decentralization.