“Cobra Kai” is back. Season 4 began on Dec. 31, 2021, and my family is watching what is perhaps the most surprising hit in a decade—and our personal favorite. The “Karate Kid” spinoff had “flop” written all over it. After several sequels and reboots, the franchise felt spent. Moreover, it was launched as part of YouTube’s ill-fated plan to compete with Amazon and Netflix in original content production. Nevertheless, “Cobra Kai” has proven a smash. After being acquired by Netflix in June 2020, the show dominated the Nielsen streaming charts, quickly racking up more than 2 billion streaming minutes. The acquisition, as Forbes put it, turned “Cobra Kai” from an obscure hit into the No. 1 show in America. The show works for several reasons and has struck a chord with young people (my kids can’t get enough of it), largely by running against postmodern sacred cows and embracing some radical ideas: self-ownership, personal …