Dang. Good thing London has Addison Lee. Edit: who are a long-running minicab service who give fixed price bids, have a reasonable app, have their own fleet by dedicated drivers, and are usually price competitive with Uber.
In many ways they are much worse. Their own corporate policies and their CEO encouraged drivers to use bus lanes, to ignore cycle super highways (to drive on them), to ignore all parking and stopping restrictions - if fines were issued the company paid for them to encourage drivers to carry on doing so in protest of not having the same access as black cabs (who in return for their training and being regulated to be accessible, etc are granted access to bus lanes and other stopping locations to ensure that accessibility can be fulfilled).
They also fell foul of using drivers without performing full background checks, etc. And their drivers are reasonably famed for not knowing where they are going (at least Uber technology saves their drivers from needing to know anything about London).