Sims 1 and 2 had the advantage that the lot was incredibly self-contained. You had a straight shoot from the spawn portal on one end to the despawn portal on the other. (Usually. There were a couple of ways the road area could get clogged, which generally caused the carpool to awkwardly warp.) This allowed for a generally controlled carpool experience.
Sims 4 has the worst of both worlds with carpools. You can't really use them for traveling like you could in sims 3, but persistent public areas around the lot would make predictable carpools a lot trickier. You'd have to spawn at a certain entry portal towards the end of the neighborhood, have possibly convoluted pathing (how would you have the car travel if the house is along a cul-de-sac?), and of course the travel time from the spawn portal to the house. The last almost certainly being complicated by townies or strays standing around blocking the car's path.
People would get upset if cars were simple teleportation objects that didn't have any drive animations, and animation/pathing issues would complicate the issue of their being used as an actual sim transit vehicle. While it's easy to say "we want cars", I wonder how many people would really prefer the extra time sink or enjoy simple teleporter cars. As with most things, it's easier when you explain how the fine details would actually work out.
