The world is already a toxic place where any kind of sane future is newly threatened daily, so why, in a summer heat wave of ugliness and political danger, do we deserve yet another dumpster fire with delusions of grandeur as nauseating and stupid as a sequel to the monumentally inconsequential Mamma Mia!? Call this embarrassing dog’s dinner Mamma Mia! Here We Go Again or just call 911. Either way, it is nearly two hours of relentless, plotless, artless junk. Considering the tack-on taste a majority of summer movie escapists live with, an inevitable gang of misguided kids will probably...