Sure there are niche markets where fully self-driving and self-driving only cars may make sense.

But they still need to handle fault cases: e.g. they cannot only rely on a beacon sent by traffic lights because that beacon or the whole traffic light might out of order. So, imho, while smart infrastructure may help self-driving cars and traffic management it does not allow you to avoid the "hard work", which to make sure self-driving cars will behave safely and reasonably completely on their own.