We don't because of cost.

With airbags we're just used to legislation for them but the same argument applies. It's not enough to say a recall is safer we have to measure the cost vs actual safety of the existing airbags

It's a strange thing with people and existing safety laws vs actual safety. For example I've advocated barriers with automatic doors at Subway and train stations to prevent pushers, jumpers falls etc. this would increase safety but no one wants to because of the cost