Until recently, gig economy giants such as Uber and Deliveroo did not have to worry about organised workers. That was almost by design: riders and drivers work alone, at strange hours, so the chances of workers suddenly gaining mass bargaining power seemed nil. That changed in 2016, when those workers started going on wildcat strikes around Europe and the US.

https://www.wired.co.uk/article/ubereats-deliveroo-joint-strike