Thank you for this. I thought I was pretty alone in thinking that "decentralization" is nonsense...albeit for different reasons. But you argue yet another perspective.

Mine is largely concentrated on macro-political: China's complete dominance of mining and mining infra/tech and the not unlikely benefits it may be aiming at by keeping the project going abroad but not at home.

Also, there are these problems:

https://medium.com/@0xdhruvluthra/the-future-of-bitcoin-mining-61be857a4f97https://www.cs.cornell.edu/~ie53/publications/btcProcFC.pdf

Stay in touch and good luck!