With good maintenance, an internal combustion car or truck can last a very long time.
Obviously the govt will be active in trying to “inspect” these vehicles off the road (safety/emissions), it may vary state by state.
Eventually, they'll be off the roads. California is going after 18 wheelers. So right now you are seeing container ships shift to the ports on the East Coast. They still depend on diesel. You can't electrify 18 wheelers yet. Maybe in 20 years. But not now.