The ADCU has been representing app drivers and couriers in the UK for years, but they're probably not the best model.
https://www.wired.com/story/adcu-gig-economy-union-toxic-rep...
The reality is that a large proportion of app workers are undocumented. Worker accounts are rented or sold to people who do not have the legal right to work. We can't reasonably address the issue of working conditions on these platforms if we don't acknowledge that fact.
https://inews.co.uk/news/deliveroo-uber-eats-just-eat-illega...
Exactly - anywhere you have undocumented or unregistered or undereducated workers you have exploitation. I don't know why this isn't discussed more widely as being a core element of the gig economy.
There isn't a technology or unionization fix for this as it's a social and polite problem. I've looked into cooperative worker-owned solutions but for certain strata of society there are more gaping problems than the algorithm.