Sounds like you are simply describing a tragedy of the commons.
Indeed, you can look at it like that. And one that can be avoided in the standard way: by not allowing unrestricted exploitation of the commons.
Even if there's no "orphaning risk" due to propagation because
of relays, etc... wouldn't miners still prefer to solve the
blocks with the biggest fees anyway?
Indeed, and absent a limit, flexcap, or forced collusion (or something no one has described yet), that is the one that involves taking pretty much all transactions
that pay any fee at all.Peter_R's argument was that a limit isn't needed to achieve this effect because orphaning will accomplish it, but we see now that he finally agrees that volume related orphaning pressures can be more or less completely sidestepped by miners:
schemes that completely eliminate block size dependent orphaning risks, it's easy to come up them.
And then he goes on to describe one of the schemes I emailed him.
Rather than cap the blocksize, I would rather raise the minimum non-zero fee, to say 1 penny.
Either pay a penny, or don't.
Consider that 200tps would give you $172,800 a day in security under such a scheme.