I can stand at any corner in any city in the USA and count the percent of cars that stop vs the percent of bikes that stop. Bikes about 1 of 10 will stop. Cars at least 4 of 5 will stop. So, cyclists, 10% compiliance. car drivers, 80% compliance.

As for license plates, I'd like both cars and bikes to obey the law. The only way I see that happening is cameras and scanners. For that to stop bikes requires the bikes to also have plates.

License plates absolutely prevent dangerous and illegal behavior in cars, just not 100% of it.