Auto companies are not service companies, those are very different things.
That said, given the dynamism of markets, there's nothing to indicate that Lyft/Uber will have any huge advantage when the time comes.
But this is a game of musical chairs - early investors need to create the biggest, most miraculous but 'believable' story so they can pass the bag onto retail investors long enough to cash out.
If retail investors were able to do their homework, or rather, if their advisors at Morgan Stanley etc. were to do their jobs, I think that they'd see there is far more risk in these things than the valuations imply.
The problem is of course is that Morgan Stanley private wealth managers, managing for all those doctors, dentists, lawyers etc. only make money if there is buying action. And the emotional excitement of 'getting in on an IPO' is just too much to ignore.
The 'bragging rights' value of your dentist in Akron Ohio being able to tell to his buddies on the golf course that 'he has an 'in' on the Lyft IPO' (not really of course, he's at the tail end), is just worth more than a scrutinized deal.
Also - notice the PR/branding for Lyft, it's so funny, like the opposite of Uber - and yet they are for all intents and purposes the very same thing.