I am saying that in a decentralized, trustless, Sybil-attackable scenario, there is also no conditional solution to BGP, because the participants have no way to conjecture the probabilities of 51% attack
We'll have to agree to disagree. As long as I can write down a solution, and write down the condition under which it applies, then I consider that a conditional solution. I do not need to state a probability that such a condition will be satisfied.
What use is a condition if it can't be measured?
The Lamport paper was aimed at hardware MTBF rates which can indeed be measured and verified.
I am into engineering. I guess you prefer black magic and voodoo (and I am from New Orleans, lol).
(nor does any solution to BGP provide all participants a consistent, provable observation when the system state is attacked).
I agree with this part.
Thanks. It is unarguable fact.
The condition of count of traitors has only utility in applications where the probabilistic rate of traitors can be conjectured.
Utility is necessarily subjective. Also, ability to conjecture a probability is subjective.
Incorrect. MTBF rates for hardware are objective engineering measurements. Seems you are referring to "feelings", "speculation" or something other than engineering.
I have also I think argued convincingly that Satoshi's PoW design (and every decentralized consensus design) must trend towards and rely on centralization. Thus the asymptotic probability of 51% attack is ~1.
See there, you just conjectured one!
Others likely conjecture a different one.
No I provided an overview of what can be put into a mathematical proof. That is objective engineering, not conjecture.
The asymptotic probability can be described quantitatively because of the inviolable economics (which derive from CAP theorem but we can prove just from the economic realities).
Though Bitcoin does have a somewhat nice recovery property in that the failure only persists as long as 50% of the CPU power is conspiring to attack it. Unlike, an airplane for example. If too many components "temporarily" fail, then it may be catastrophically disassembled before they recover.
I can think of scenarios where that isn't necessarily true. For example, such an attack convinces speculators that the attack can be repeated at-will and so they flee the coin. Crash and burn.
The system can still recover. There is no catastrophic disassembly.
Non-sequitor.
You will never convince all the speculators to leave either. It is a bit like infinite divisibility. You have infinite reducibility of speculative value. Altcoin at #1000 in market cap still has a (tiny) value, there is still a (tiny) incentive to mine, and its blockchain still functions.
For all intent & purposes, shitcoins that have $10 floats are dead and will fully die eventually.