Well the band wagon has turned 180, now it’s fashionable to point out the flaws. My issue with this kind of videos is really, where are you in the early days of the hype, when the public needed cautions the most? A convenient naysayer when all the actual hard works have been done elsewhere
“Trapping electrons in a crystal” is such a nonsensical way of conveying the idea of a flat band. Most isolated crystals trap all the electrons they have inside of them, or else the world will be full of free roaming electrons!