The point is after wasting $15 million, Ethereum is no closer to a solution than when they started. And they are moving further in the wrong direction away from any decentralized solution.

(they are moving towards a centralized result and obscuring that it is centralized in technobabble, yet they are also adding so much complexity that I think it might diverge/disintegrate/malfunction as well as being a failure due to being centralized ... and they may not even fully comprehend this which is indicative of the mess... )

I didn't read the whole thread so maybe this is covered but the reason* these attacks don't happen in practice is that none of the deployed chains actually operate as decentralized consensus systems. They are centralized in some manner with checkpoints, centrally signed blocks, etc.

This makes them impossible to attack but it also makes them a sham. They're just centralized systems implemented in an inefficient way that gives the appearance of decentralization.

* The other reason these systems aren't necessarily attacked is that attacking takes work...