Actually I think the video has some points. I'm pretty sure it's serious. It pictures the difficulty of dating multiple partners rather well. I mean yes, they think poly is just about enhancing your sex life, but since that is a huge motivation for a lot of polycurious newbies, they've certainly got audience to speak to.
Btw. I've listened to some more of those 'school of life' videos, and my feeling is, a lot of them suffer a similar bug. They take some pretty advanced idea, they often do in-debth historical and philosophical research, they convey interesting thoughts I didn't know about ... and then they totally blow it for me by jumping to some ethically biased conclusion. It's not uninteresting, but I'm picky about what to take from them.