Some helpful caption/subtitles is for videos which don’t have dialogue but add information to what’s going on. One example is primitive technology but there are plenty of other skill presentations/tutorials where the how and why is spelled out in the subtitles while the actual audio is just peaceful melodies to enjoy watching someone work too.
I think you’re also missing the caveat of different levels or types of stupidity. Musk bares the resemblance of the “Emperor with No Clothes” type. Even if he’s aware, he’s still parading around like he’s the greatest while everyone thinks he’s a fool for his actions. It’s definitely a certain level of stupidity to pull that off without self reflection.