the primary way the question makes sense is as an investment choice. If you have XXXX dollars to invest in crypto, you do have a zero sum choice to make.

loved your analysis of BTC security. But here is the fly in your ointment:

Imagine the communist party decided it was in its interest to destroy BTC. Many of the mining rigs are physically located in China. I am sure the party knows which buildings most are in.

They could announce you must patch your rig and if you don't, it will forcably be done, and you will be sent to prison. I think if they had thousands of agents in the field knocking down doors, the millions of owners would quickly start patching their systems. In matter of days the world knows the communist party can execute a 51% attack anytime they want.

Value would PLUMMET. 90+% value would be lost overnight. Then it would continue it slide further as the party stragically made bits of money with destabalizing double spends.

The only fix I can imagine for this situation would be for the remainder of the network to black list this greater hash power. but there is currently no mechanism in place to do this, nor governing committee to even contemplate it. Furthermore they could continue to screw with the remaining network if they had establish 100 relationships with smaller players in other countries. They could use their greater hash power to inject short double spend chains into that network all over the place.

Perhaps this could be avoided if we had protocols for double-spend detection and black listing. In that case the best the party could hope for is a hard fork that left all of the chinese rigs on a worthless chain.

Now what are the chances? Well as long as wealthy Chinese citizens own bitcoin, then it seems less likely. But imagine:

(1) the party creates a competing crypto.

(2) Then the party bans the owning of more than XXXX in bitcoin for more than 1 month.

(3) Citizen's divest, and miners sell quickly as the earn them.

(4) PRC explodes the BTC chain, and converts this hash into value for its chain.

This would be a sort of economic act of war against other nations, so this would not happen unless relations with USA and others were at a pretty low point.

But all of this still suggest BTC is less secure than you imply.