For me, the futility of GOFAI is obvious from simple introspection: is my own brain capable of chaining through vast networks of propositional statements? I wish! I can barely hold a 5 node decision tree in my head while playing a board game. At the same time, my brain is amazingly good at parsing visual and linguistic stimuli.
Still, you have to respect the man's dedication to his quixotic quest.
But wouldn't that kind of reasoning also say that helicopters are impossible because no flying animal works that way?
For a more reasoning-adjacent example, "conventional" chess AIs don't really work like brains do, either, but they're pretty good at playing chess.
Yeah but helicopters fly. The problem with cyc is that it never really got off the ground.
Symbolic AI wasn't a failure but it never really worked for any problem space without rigid rules you could define and that's with some of the greatest minds trying for decades to make it happen.
At this point real-world intelligent symbolic AI only exists in fiction and our collective imaginations. Technically, no one has proven it can't work, but at some point you have to face the reality.