This is not 100% on topic, but I've noticed something weird. The price estimate is the same from Las Vegas airport to the strip as it is to downtown. The indicated route to the strip uses the I-215 tunnel, which is very much out of the way (and a favorite for taxi drivers who want to inflate the fare) while the route to downtown takes the more direct Swenson to Tropicana.
But yes, the quoted fare is based on estimated time and distance, but if the actual for the trip varies a lot, the fare is recalculated. In one respect it's almost required, because if the passenger wants to make a stop or divert the route, the driver would have to say no if the fare didn't reflect these.
As a driver, I would always require the passenger to change the destination in the app if it was relevant, to avoid fussing about "not the quoted fare." But I also advised pax to put the final destination in the request and then just tell the driver where to go if they (for example) wanted to drop off other pax. When I stopped driving, Lyft allowed you to specify multiple destinations but Uber didn't.