The allure of a franchise is that it offers more of something you love, ostensibly buffed up and freshened—it’s newness with sameness built in. The James Bond movies, the Thin Man comedies of the 1930s and 1940s, a long, undulating string of Rocky pictures stretching from 1976 to pretty much yesterday: franchises are nothing new, because the instant Hollywood sees one dollar sign, it starts sniffing the trail for the next. Audiences respond as they’re conditioned to, wanting more of something they loved last year, or the year before, or even in the previous decade. In the case of the Marvel Cinematic Universe, the cycle is apparently endless, perhaps stretching beyond even our children’s lifetimes. No one who’s making money off a current f…