First up, if you're reading the book from labour-oriented perspective you may find the start of the book a bit unsettling. There are a series of stories about individual gig workers that run through the book, and in the early stages these are positive. People talk about the freedom and flexibility associated with gig/platform work, and the ability to get started and start earning quickly.
I bet a lot of people who share similar views to me will be thinking (yeah... but....!) while reading this. I know I did. But I think that it's really important that those of us who are interested in working practices, and changes to them, never lose sight of the fact that these are the real emotional responses of real gig workers. The picture is complicated, but people who do this work do find positives relative to traditional employment.
Second, that said, in almost all the individual cases the stories turn sour. Workers find it hard to make the kind of money that they were promised (Uber drivers in particular), experience a level of control more associated with normal employment etc (an important point here is the difficulty in changing unpleasant features of apps etc) and so on.
Another point here is that support for "flexibility" is linked to how well you are likely to do. If you're a highly-skilled worker it all looks good. If you're on Mechanical Turk tagging photos for pennies, or an Uber driver making a few quid an hour after costs, it's not so great.
Third, a lot of gig working looks a lot like poor employment practices in other bits of the economy. Here's a good example of a guy call Gary who worked as a customer services call centre operator from his home, picking up jobs online:
Imagine a nesting doll with Gary at the centre: Gary was the smallest doll, and independent contractor working for the [Independent Business Operator]. Go one layer bigger, and you'd see the IBO (the small business that hired Gary). Another layer bigger, and you'd see Arise, the big customer service company that had made a contract with the IBO. Only after another layer would you find Sears, the company that the customer thought he was dealing with.This multi-level supply chain is the same that you see in transport (delivery for example).
Similarly, the way that the work is pitched to workers doesn't really differ much from how temp agencies pitched to female workers decades ago. And the model of seeking an arm's length relationship workers, paying them only for work done with no formal employment or commitment to benefits etc is obviously not new.
Fourth, a lot of the gig economy companies didn't set out thinking of themselves as employers, and have struggled to come to terms with employment relationships. What comes across in the book quite strongly from the story of Managed by Q, is that tech start-ups just didn't think about these issues at all. They just thought about technology. I don't think this is a justification for their employment model, and obviously subsequently companies have had a choice how to address these questions. I don't think you can look at Uber now and think it doesn't know exactly what the issues are, it is simply trying to protect its model for as long as possible.
Fifth, that said, some gig economy employers have shifted towards a more traditional employment model (ie they actually employ workers) and have made it work. There is a decent section on the Good Jobs Strategy here (which doesn't really include unions...). Labour costs go up, but so does retention, motivation etc. This seems worthy of more investigation
Sixth, unions are in the mix, but primarily in shifting the model back towards formal employment. There are quite a lot of references to unions throughout the book - in terms of gig worker interest in them, union reactions to gig work, policy ideas and so on. But there aren't good examples of unions managing to represent gig workers effectively. This is probably partly because the book is largely US-focused and partly because of the difficulties in independent contractors taking collective action. Where unions have made a few dents is in successfully challenging the employment status of gig workers.
Overall there is still little agreement on the way forward. Most of the big gig economy players do not want to change their model, and their proposals on issues such as portable benefits are (again in the US context) very limited. They seem to be quite happy sticking to the "workers like flexibility and being their own boss" mantra. Business-friendly politicians and regulators do not want to intervene significantly (the UK's Taylor Review is a good example). I suspect until there is more policy intervention there will be a slow grind of legal cases (like the challenges to Uber all over the world) that end up determining employment relationships. This seems like a highly unsatisfactory way to decide the future of work, especially when the corporates have deep coffers they are willing to use to defend their model.