I enjoy how deep into the programming that speedrunners are able to comprehend and exploit. For example, the infinite universe Mario 64 teleport stuff is nuts.
Speedrunning can be fascinating, and this is probably this guy's best video. All the others fall in the rut of "There's this game, and this guy set the record, and then some other guy set another record, and nobody thought it could be beaten, and that was proven wrong when these other people went back and forth breaking each others records..." If he focused on the technical details they'd be golden.