I've read through the judgement, and it took multiple readings and flipping back and forth between sections to get my head (I hope!) around what was going on. Based on some of the comments here I'd thought I'd post my (IANAL) take on whats going on.
The TLDR version is that Uber contract management fucked up, they fucked up big time. This issue is solely down to poorly (in fact not at all) established contractual relationships.
The judgement itself is not about gig workers (which I wish it was) in general, it is about the actual relationships established between the drivers and the booking agent, Uber London.
Drivers - the ones Uber claim are independent contractors, but who claim (and won) that they are 'workers'1. Under UK law, these are Hire Car operators and must have a Hire Car License.
Users - aka us, the people who engage Uber/dirvers for transport services.
Uber - the US Uber parent, who isn't legally in this picture as all the various services are provided by wholely owned subsidaries incorporated in UK/Europe.
Uber BV - one of Ubers aforementioned subsidiaries, incorporated in the Netherlands. This is who drivers have an independent contractor contractual arrangement with.
Uber London - another of Uber's aforementioned subsidaries, this time incorporated in the UK. Because UK hire car law requires both drivers and anyone acting as a booking agent for hire cars to have a Hire Car License, this Uber subsidiary is the one who holds the Hire Car License for the London region so it can act as a booking agent for Hire Cars.
The process Uber says of a User booking a transport service from Uber London is as follows:
1. User fires up the Uber app, and (if they haven't already) agree to the various Terms and Conditions of usage, which establish a relationship between the User and the booking agent, Uber London, and allows Uber London to act on their behalf.
2. Uber London finds an available Driver, and books that Driver to perform the transport service.
3. Once a Driver is booked, Uber London 'hands off' the contractual services to the Driver, so that the contract is now between the Driver and the User, not Uber London, with Uber London having fulfilled it's 'booking agent' services and passed the contractual responsibility onto the independently contracted Driver.
4. Driver picks up passenger, etc. [rest is not necessary to explain Ubers problem].
Some of you may have noticed a problem with the above process, and as the judgement itself states (Paragraph 51, last sentence thereof):
It is, however, trite law that a person (A) cannot create a contract between another person (B) and a third party merely by claiming or purporting to do so but only if A is (actually or ostensibly) authorised by B to act as B’s agent.
What the judges are pointing out here is that there is no contractual relationship - express or implied, written or oral - between the booking agent, Uber London, and the Drivers allowing Uber London to act as an agent to the Drivers and establishing a contract on their behalf (the Drivers are 'B'). The Independent Contractor relationship the drivers have is with the Dutch Uber BV of Uber, not the Uber London subsidiary acting as booking agent.
Since there is no such relationship between Uber London and the Drivers, the employment tribunal (which this is appealing) fell back onto traditional deductive methods to determine what sort of relationship there was. Therefore based on the type of work performed, how it was performed, how it was engaged, how it was controlled, what influence Uber London had over the drivers and the assigning of the transport work to the Drivers, they determined that the best fit for that relationship was 'Worker', not Independent Contractor, not Employee.
Again IANAL, but I think Uber's solution to this problem going forward is to make sure Drivers establish their contracts establishing them as Indpendent Contractors with the actual booking agent corporation, Uber London, instead of the non-involved in the booking process Uber BV corporation.
So as I said at the start, this is not about 'gig' workers, in the end Uber just fucked up their contractual arrangements, so were left to the mercy of how the employment tribunal viewed the relationship, and they viewed the contract-less relationship as a 'workers' relationship.
1 Apparently under UK employment law, there are 3 types of, err, service providers, employees, workers and independent contractors. Employees have full rights and protections such as against unfair dismissal, minimum wages, paid holidays, various insurances, etc. Workers are an employee 'light', they have no unfair dismissal protections - so are 'at will' - but still have entitlements such as minimum wages, paid holidays, insurances, etc. Independent contractors are, well, contractors, little or no protections, no insurance (except what they pay for themselves), no holidays, no unfair dismissal protections, etc.