Peak pricing can spread out demand a bit, and also, people can use much smaller vehicles most of the time. We buy cars for worst case size or conditions. Look around the parking lot of a white collar work place that is filled up with four wheel drive all terrain vehicles and pickup trucks.
Ride sharing for rush hour would use a ton of compact vehicles. Even if the number of vehicles is the same to account for peak usage, the majority of the vehicles will be much smaller and much less capable, and therefore much less profitable for manufacturers.
