Near the end of Christopher Durang’s play “Vanya and Sonia and Masha and Spike,” one of its titular characters, named after a famous creation of Anton Chekhov, unspools a lengthy monologue about the good ol’ days. Things were a lot better half a century ago, Vanya admits. Humans were more connected. Technology hadn’t become a mass distraction. Popular culture was admittedly simplistic, but it was more wholesome. “The ’50s were idiotic,” Vanya says, “but I miss them.”