It has been a bittersweet experience watching the final seven episodes of Pen15 (available on Sky Comedy and Now in the UK and Hulu in the US), the cringe-inducing high-school comedy that sees thirtysomething comics Maya Erskine and Anna Konkle play 13-year-old versions of themselves (amid a cast of actual teens). The show is as brilliant and bracing as ever, full of adolescent angst, absurdist humour and the occasional moment of devastating drama. But until these episodes arrived, there was no indication that they would be the show’s last. When that news broke, the assumption was that Pen15 – a little-watched if critically beloved comedy – had been cancelled, but that wasn’t the case: Erskine and Konkle have both just had children and have tons of other commitments (Erskine is in the upcoming Obi-Wan Kenobi series; Konkle is writing a memoir), so were conscious of burning out, and – crucially – felt that they had told their characters’ story. Still, it’s hard not to feel like Pen15 has gone too soon. This is a pretty common feeling these days. The promise of the streaming revolution was that you would get more of what you wanted, when you wanted – and the expectation was that that would extend to shows getting to tell their stories over as many series as required. After all, one of Netflix’s earliest moves was to revive the beloved and prematurely cancelled show Arrested Development (a move that didn’t go so well). In actuality, though, the length of a series in the streaming age tends to be pretty short. Really, we should have seen this coming: streaming platforms – with their algorithmic models predicated on figuring out who is watching their content where, when and why – were always likely to make ruthless decisions on when to cut a show loose. Indeed Netflix has been particularly brutal in this regard (Glow, we hardly knew thee). But Pen15 illustrates another reason that shows aren’t sticking around for long: the talent. Creating TV, particularly in an age where quite a few shows resemble blockbuster movies in their scope and budget, is an intense, laborious experience, so the old model of series trundling on into their sixth, seventh or eighth year hardly feels fit for purpose (it is hard at this point to imagine a show like Succession, so operatically full-on every week, being able to maintain that intensity for another five or six years). And, of course, these days TV has become a desirable place for Hollywood A-listers, whose schedules – not to mention salaries – don’t chime terribly well with multi-series epics. That is why, in the past half decade or so, we have witnessed the rise of the limited or mini series: self-contained stories that get told within a tight 10 episodes or fewer. A superstar such as Kate Winslet can take on Mare of Easttown knowing that she isn’t signing her life away to a multi-series show. And it’s also why there has been an increase in anthology shows such as American Crime Story or Black Mirror, with a different cast every series or even episode. Brevity has its benefits, too: attracting a higher calibre of talent (take Barry Jenkins directing all 10 episodes of The Underground Railroad), and allowing its creators to tell ambitious, tightly constructed stories, with none of the wheel-spinning or forced cliffhangers that a longer, baggier show might necessitate. Such programmes don’t outstay their welcome. Strikingly, of the top three shows on the Guardian’s best TV of 2021 list, two were limited series (Mare of Easttown, It’s a Sin) and one was an anthology series (The White Lotus, whose second season will have a different setting and cast, including – excitingly – The Sopranos’ Michael Imperioli). Still, it is hard not to feel a pang of regret for the TV that we have lost: those vast, “novelistic” series like The Sopranos and The Wire, aren’t gone necessarily, but they’re certainly harder to get made. (Although we should note that on US “network” TV, the never-ending show is still the model, in the form of procedurals such as CSI or comedies such as The Simpsons). And it’s hard not to feel sadness too for the shows that disappeared right as they seemed to be hitting their stride. I personally could have watched … oh, another 15 series of Pen15.