I don't know, in most countries judges are appointed by the government after advise from independent advisory boards. Then again, in most countries judges have a lot less power than what it seems like they do in the US and the legal system is not a political battleground.

The US has a really quite unique judicial system, and in many ways ultimate sovereignty of the USA resides in the Supreme court. That power has filtered down to lower courts who make various rulings that will shape what things the higher courts consider on appeal.

Courts can say whatever they like, it comes down to the executive branch to enforce it.

The courts are the ultimate source of legitimacy.

Every time an executive defies the courts they erode the basis of their own power, and their public image as a legitimate executive.

Look at what actually happens to executives who defy the courts. The level and types of protest people feel are legitimate increases dramatically. Once the court said that "well technically the emergency order only lasts for 30 days" the anti-mask brigade was much more vocal and flagrant about it.

Free and fair elections are the ultimate source of legitimacy. The courts have maintained good publicity in our rigged system, but they don’t have any inherent legitimacy of their own.