The problem with that is that laws depend on each other. If you take a good law from a different system without refactoring your system - you are more likely th

The problem with that is that laws depend on each other. If you take a good law from a different system without refactoring your system - you are more likely than not to cause unintended consequences. For example sentences in criminal code must be proportional to other sentences (if you punish rape worse than murder you increase the number of rape victims that are immediately murdered for one example). There's also different systems, in some you add up sentences, in others you only serve the longest sentence. In some you can be punished for the same crime in 2 different aspects, in others you only get one of them prosecuted. There's a lot of details and interdependencies, and even the cultural assumptions and demographics play a big role. Some laws that work in a country with uniformly wealthy population won't work in a country with big inequalities. TL;DR: you can't copy-paste laws between countries without their dependencies :)