but if they are entering markets where Uber already exists, wouldn't there users mainly be ex-uber users ? unlikely that all of them are new users. Unless people user both at the same time, but it could still eat into ubers revenue in those regions.
... and ex-Uber drivers — meaning drivers who were kicked off Uber due to poor user ratings. This would explain what's going on with Lyft's intro to Canada right now. Awful customer service every time I've used Lyft.
A similar situation was seen in India, when Uber entered the market. Most of the then-existing hail-taxi users were users of Ola (the home-grown service). Users here use both apps at the same time (comparing ride prices to make the choice). This meaning Uber and Ola eat into each other's revenues and markets across cities in India.