No television series should be a seven-hour film. (Or eight, or ten.) This has been a recurring point of discussion over the years as the TV business labored through concepts of prestige imported from cinema, luxuriating in the excesses of its “golden era” and, later, Peak TV. Now that the biz has settled into a period of austerity, recent trends indicate a rediscovery of certain lessons from the grand old days of television: things like how it should be pleasurable...