Fallibilism, correctly understood, implies the possibility, not the impossibility, of knowledge, because the very concept of error, if taken seriously, implies that truth exists and can be found. The inherent limitation on human reason, that it can never find solid foundations for ideas, does not constitute any sort of limit on the creation of objective knowledge nor, therefore, on progress. The absence of foundation, whether infallible or probable, is no loss to anyone except tyrants and charlatans, because what the rest of us want from ideas is their content, not their provenance: If your disease has been cured by medical science, and you then become aware that science never proves anything but only disproves theories (and then only tentatively), you do not respond “oh dear, I’ll just have to die, then.”
The theory of knowledge is a tightrope that is the only path from A to B, with a long, hard drop for anyone who steps off on one side into “knowledge is impossible, progress is an illusion” or on the other side into “I must be right, or at least probably right.” Indeed, infallibilism and nihilism are twins. Both fail to understand that mistakes are not only inevitable, they are correctable (fallibly). Which is why they both abhor institutions of substantive criticism and error correction, and denigrate rational thought as useless or fraudulent. They both justify the same tyrannies. They both justify each other.
As a mere pseudo-philosopher, it pleases me to see recognized thinkers arriving at the same conclusions that I have through my plucky, can-think spirit.