Californian Uber driver Annette breaks down in tears at the wheel of the car she can scarcely afford to fill with gas. In Lagos, Mitchell rarely sleeps through the night for fear of missing out on one of the more lucrative online tasks listed on Mechanical Turk. In Paris, Leila tries to wrangle backpay for a fellow Deliveroo rider who was grievously injured on the job. These and dozens of other stories are the bite-sized examples of the everyday cruelty and dehumanization of the gig economy, the ever-expanding system of global capitalist exploitation that Shannon Walsh’s almost paradoxically fresh-faced and accessible documentary “The Gig Is Up” aims to highlight. The gig economy itself is bigger even than Walsh’s globetrotting film suggests, also involving offline seasonal jobs, on-call work and all manner of temporary contracts (a freelance film critic clears her throat nervously). But here the focus is on the kind of casual employment that is mediated through online platforms, from the more visible services like Uber, Deliveroo, Lyft and TaskRabbit (as well as Chinese iterations fielded by corporations like Tencent and Alibaba) to the “ghost work” performed through businesses such as Mechanical Turk (MTurk), Amazon’s massive, crowdsourced labor offering. To demystify a landscape that hides behind anodyne-sounding jargon in much the same way that rival food delivery services brand their riders in cheerfully color-coded rainjackets, Walsh has a panel of authors, entrepreneurs and journalists to hand. These experts provide valuable pattern-identification and big-picture context for a dauntingly labyrinthine system in which it can be hard for us laypeople — the end users of many of these services — to understand the ethical impact of the choices we make. But Walsh’s real agenda lies in the individual stories she uncovers from the workers on the frontlines, the unter class created by the Uber economy. In DP Étienne Roussy’s appealing, easy-on-the-eye portraiture, we move from a Nigerian MTurker doing transcription work in a cab snarled up in traffic, to the TaskRabbiter son of a carpenter assembling a family’s Ikea wardrobe, to a Shenzhen landfill in which hundreds of thousands of branded bicycles — casualties of the food-delivery-service wars — are piled up like skeletons in a mass grave. These snapshots are variously chilling, galvanizing and moving, especially when it becomes clear how much the full-time Uber driver or year-round MTurker is made to feel personally responsible for their dwindling incomes. There is a kind of Machievellian genius in a company outsourcing everything to its workers — even their own exploitation. At times, however, you can almost feel Walsh’s instincts pulling away from the main thrust of her argument as she happens on a personality whose point of view is less representative of the wider issues than intricately interesting in its own right. Jason, an online worker living on the poverty line in Mims, Florida, with his scratchcard-addict mother, is a case in point. His cheerful grifting of the MTurk system (for the purposes of some survey work, the gold-toothed, white ex-con presents himself as “a Black republican”) could serve as the subject of an entire film, one in which the sheer pointlessness of so much of this “work” is also examined. As insightful as it often is, “The Gig Is Up” sets itself a remit that is just too broad to fully explore in its brisk 89 minutes. It’s not just that individual stories are necessarily curtailed, a lot of the film’s most provocative strands remain underdeveloped. The conundrum by which these companies can establish such influential monopolies, acquire expensive premises, and have a huge share value while also declaring a deficit. The irony of quitting a job because you want to “be your own boss” but discovering you’re now the underling of an algorithm. The “Black Mirror”-esque dystopia that is one poor rating, from an unthinking customer, cratering your reputation and killing your earnings potential. And the absolutely chilling omnipresence of some of these corporations: If there is a polite word to describe the practice of Amazon paying overseas casual workers in Amazon gift cards, I don’t know what it is. “I don’t think of it as real money. It’s … Amazon money,” says MTurker Tomisin, his face changing as he realizes he’s coined a phrase that essentially acknowledges the tech giant’s imperviousness to traditional economic principles: It is an economy. Walsh’s film, which certainly rates a 4.7 or higher for timeliness, does include some hopeful green shoots in the form of emerging activism movements aimed at extending basic worker protections to parts of this newly emerged workforce. But the overall effect of this fast-paced, broad-based but scattered primer is to show how difficult solidarity is to achieve when so many buy into the gig economy’s promise of freedom and egalitarianism, and only find out it’s a lie when they’re too far in to get out.