1) Uber's upfront estimate is based on a naive calculation of getting from A -> B. From a software perspective, that makes sense. The consumer hasn't even committed to riding, so let's just toss out a ballpark figure.
2) If the consumer looks at the figure and says, "Yes, that's reasonable for transportation from A -> B", which they indicate by clicking "Request Ride", then they are agreeing to pay that price for the service.
3) The rider can verbally request a different route once in the Uber.
4) The driver is paid based on minutes and miles, via some formula that they've agreed to. The rider is charged based on an up-front calculation, which they can decide if it is worth it or not.
It sounds like the lawsuit is alleging that the rider is being defrauded by being taken on a different route than the one displayed at time of purchase.
I think this is silly because, to my knowledge, everyone taking an Uber is paying for the transportation and not any particular route. I.e. being taken on a specific route isn't what the rider is agreeing to pay for. Also, as noted in (3), the rider is always free to change the route.
Additionally silly because the rider seems to be alleging that they were defrauded by being taken by a more efficient route. There just doesn't seem to be any "harm" in what's happening here. I can understand the case if the user agreed to go from San Francisco down to San Jose, based on a route straight down the 101 highway, then, once they got in, was driven to San Jose through Los Angeles.