Unless you only make 1-way trips, you still need to get from B back to A, so it's much more efficient to have a car that does these smaller individual legs of a trip for multiple people without needing parking space at every destination. Even better if that car can carry multiple people at the same time.

You're underestimating how severely restricted the parking supply here is via simple physics. It's not just driving from A to B, it's driving from A to B and then circling around for 15 or more minutes trying to find a parking spot.

In many places, parking at your destination is more restricted than road space along the way to your destination.

You'd need to allocate more parking spaces then. You can have more roads if you have less parking.

Also, having a car sit idle 95% of the time is not an efficient use of money. It's the same model as virtualization with servers (sharing unused capacity brings down the costs for everyone).

Also, there's the tremendous amount of time wasted and hassle to park, especially in big cities that have multi-story parking garages. Especially with their "compact" parking spots that even compact cars have trouble fitting into.

On the other hand utilization in the ownership case is very low, which therefore consumes lots of parking space which... consumes lots of street space which... reduces total bandwidth.

Another factor is that the mere existence of options like Uber and Lyft likely means people take trips they otherwise would not.

The thing Uber/Lyft do remove is the need for so much parking. On the flip side, do they need more places to idle and await new rides, if we don't want them to congest roadways while doing that.

Serious???? Did you forget parking... Wasting 20 mins to 50 mins on parking