Rekrunner's whole argument reminds me of a common, paranoid thought that a lot of people experience growing up: that you're very dumb, mentally handicapped, and and everyone else is aware of it and just puts on a charade around you. I've spoken to a lot of people who have experienced this, I remember thinking about it in first grade—what if everyone is just humoring me, this whole school is a fake, my brain works so slow compared to everyone else's, etc... I've heard this same thought in regards to friendship, something like "my parents just pay these people to be my friends." A more common riff that adults experience is "are these people actually my friends?" It's a common paranoid delusion with endless variations, interesting to read about, almost a shared human experience.
The deal is, most people get older and put the pieces together. I've seen an overwhelming amount of evidence that I'm not being hyper-sheltered: I've gone on to graduate college, get jobs, travel, etc... With each of these feats of independence, coupled with years of observation, the possibility of me being absolute dumb as dirt diminishes. I can finally, and proudly, say that I am not mentally handicapped and everyone in the world is not "in on it".
Now, what if I really am just that dumb? I guess it's possible. Everyone would just have to be that much smarter than me. After all, in this scenario, I'm super dumb. I can not rule out entirely, with 100% certainty, that that's the way it goes. But I'm so positive that's not the case. I do all the same things that functioning, well-adjusted adults do, they can't keep up the charade this long, this well, right?
Rekrunner's entire argument hinges on my final question mark. The near-zero probability that something , anything else could be true. I never seriously entertain this idea that I'm being coddled by society anymore (outside of entertaining a conversation), because I've seen the evidence and it's overwhelming.