I certainly agree we will likely not own cars anymore sometime int he further, we will share them with others, more indeed like cabs. Will these be electrical or still with gazoline? For some time we will indeed have gazoline, but more and more electrical versions will come on the roads. I think in about 20 to 30 years AI will become part of our daily lives at many different places. We are at the start of a new industrial revolution.
We are, and we can't just say like: "Okay for now on no one is allowed to drive a gazoline", people just need time to adjust. We need an in between solution, for now. For example an other road for these cars for now (just like bicycles have) pushing technology isn't good either.
I think self driven cars can mix with the traditional traffic on the roads. Whether they are 100% electrical or not, doesn't matter. Actually I think self driven cars may be there in larger quantities then electrical cars. They are not related and I'n sure kits will ve developer to upgrade a traditional car to become self driven and new fuel cars will be manufacturer with self driving capabilities. Push for technology, well it is all about the supply side and thr price. When price right, then the market will buy. Laws will also gradually chance. Governments may even stimulate self driven cars because of the higher level of safety that self driven cars will bring.
I think it would be more expensive to upgrade, and I think if we would mix them with traditional traffic we would see an improvement for sure, but we could achieve way more if we have roads where only AI cars are able to ride.
It won't be for now, that's why the mix is yet another in between solution because in the beginning there won't be that much on the road.