You are twisting words beyon any coherent meaning.
> It's a proof that something is possible to show one example.
Agreed.
> the proof has been the historical behavior of miners after years of RandomX.
> Nobody said it would be eternally or entirely resistant to optimizations...
These are contradictory statements. If historical behavior was a proof, then it would be eternally and entirely resistant.
The limit we set at the beginning was "no one can design a custom device for RandomX with more than a 2:1 efficiency advantage over general purpose CPUs". That is and will forever remain true.
In reality, no one has been able to build any device for RandomX that isn't actually a CPU. The closest thing to a "mining ASIC" is just a bunch of RISC-V cores.