The best way to stop pedestrians being killed on zebra crossings or any other official crossings is to have a barrier
You surely can't mean that? Do you drive in the UK? (your profile says you live there). From your outwardly pro-car bias, you likely do. The Highway Code is very clear:
"Move ahead when it is safe to do so, proceeding at a speed that is appropriate to the conditions, and paying attention to other road users." The term road users also clearly refers to pedestrians crossing the road.
Your opinion is completely about face in my view. It is the pedestrian that has the right of way, not the car. When you are driving near a pedestrian crossing, you should be assuming that there is the
possibility that the person will step out, and drive accordingly. As to legal action in the event of a collision, that is for the police and their witnesses to note and for the courts to decide.
The Belisha beacon flashing warning light has saved literally thousands of lives, and Polish roads are a deathtrap, and badly need something similar, so that drivers can clearly see where the pedestrian crossing is. I blame the town halls for being filled with idiots (and that includes town planners and engineers) who have no real concept of how dark and insufficiently signposted pedestrian crossings are.
It really is a scandal, and it needs addressing urgently, but not with barriers for pedestrians - as I stated, you place the car first, and that has no legal standpoint.