That is certainly the model - what Uber is trying to do ultimately, or Elon Musk's self driving technology. You don't own a car, you hale one.
But I don't think this has been thought through - on a pure technical basis. Because everyone needs to go at the same time, so you still need as many cars. Everyone goes to work and comes back at around the same time. The ball game is at a specific time. So you still need lots of cars. Maybe ride sharing solves some of that, but there are 283M cars now. The argument was that the typical car sits 99% of the time so you only need 1% of the cars, but I think its probably 25% at least. Are corporate's going to pay for 75M Ubers? Maybe - but I just don't see this working.
I think they thought work from home and such would negate a lot of need - but no one actually works from home - they goof off.
I do agree with saving all you can the worst is yet to come - but that has almost always been the case. For the last century there has been a major cataclysmic type event every 10 or 15 years. WW1, great depression, WW2, Cold War, Oil Embargo, 70's inflation, .com bust, 9/11, Great financial crisis, pandemic. We get through all of them and come out better on the other side, but having some acorns in the tree is a good thing.