> The stakers (and their adjoints) can collude and decide to reorg the chain for a different outcome. This can be done indefinitely at no additional cost.

No, they can't. As a part of the attack they will have to produce a two different signatures for the same decision (block N has hash X). This is where slashing comes in - anyone can submit those signatures to the chain to slash signers.

Not to mention the cavalier attitude towards their tokenomics (quite literally monetary policy now), how often they can change it. It simply doesn't inspire confidence. A monetary layer should be immutable once a good set of rules have been found to be working well.

Just think about it, if a protocol layer on the internet changes its protocol parameters based on some trends, is it a good idea? Bitcoin is like another protocol layer on the internet protocol stack, you build other layers on top of the base monetary layer. You reduce the possibility of bugs in a layer disrupting the whole ecosystem and make the layer more maintainable.