what a mess!
I think you are over-egging the case against Jumbo; they still look by far the strongest team and IMO Soudal Quick-Step were morons for putting Serry on the front in stage 2. They need to race smart because they are overmatched in terms of strength.
One point you did not mention in your analysis: cycling is still a sport in which scores are kept - and settled. It is within the power of even weak teams to make the race hard at a moment of their choosing, which might be quite inconvenient for your team. Teams mostly follow the unwritten rules because they are tangibly enforced. Once all sports were like this; perhaps cycling only remains an outlier because it is still relatively poorly paid.
But we can agree that this Vuelta is a total shitshow. I'm hoping the CPA will force some changes as a result. Union strong, baby.