They are a menace.
they are forcing traditional black cabs off the road.
they pick up from flag-downs on the street which is against the by-laws.
most of the drivers live outside London in places like Peterboro, Cambridge reading and drive into the city with no knowledge of the streets at all. do everything on sat nav.
Whilst using above cannot concentrate on the traffic which is a 100% must in central lLndon and slowdown all the traffic even more crawling while they look at their screens.
Screening, the drivers are not screened properly and there is evidence of sexual abuse and assault by vheir drivers.
they have been found to be driving for up to 24 hours at a go thereby endangering other road users including cyclists, pedestrians and their own passengers.

There is nothing wrong with local London mini cab firms. If the know you and you're a good customer they look after you. I have found Uber to be the worst option every time.