I don’t think the problem with Fasten, Fare, and GetMe is their inability to scale. I’ve been able to get rides when I needed them using the apps (albeit, it takes a little longer than U/L). The biggest problem I see with them is PR. 90% of the people I mention those services to have never heard of them.
Also, as a side note, their customer service sucks and all the drivers I’ve had on any of them are drivers who were previously removed from U/L for bad service, driving, etc. And quite honestly, they shouldn’t be driving. It’s like starting all over again from ground zero.