to be fair if someone does not buy a car because a car driving service is a doable alternative and its per ride so they decide to walk or bike a bit more to save some money on a case by case basis and then also if the driving service is a bit efficient in a traveling salesman kind of way and then if they tend more toward fuel efficient vehicles (since the person who buys a truck or suv may be doing it because they may need the capability or not having the infrastucture in their apartment to plug in an electric). I could see it reducing emmisions. Even a decent chance of doing it. Same if a multicar family decides they can just go with one car.