[ovi256]

>Why can’t the taxi companies compete by building an app that provides the booking part?

Yes, why can't they ? Turns out building apps users will use is not a commodity that can be bought off the shelf.

[TeMPOraL]

Actually, those apps are very much a commodity. Everyone and their dog has one. However, users are price-sensitive, and apps need marketing - both of those concerns turn competition into money spending game; Uber has more money and exploits the international scale of their business.