> The largest EU benefit is that it makes democratic and rule of law backsliding unlikely.

On the contrary. Since the EU has no meaningful penalty mechanism other than withholding funds, and enormous capacity for shared damage absorption, once a country passes a certain threshold of development membership in the EU actually encourages government misbehavior including democratic backsliding, because it insulates the government from many potential adverse consequences.

For example, governments around the world have to fear violent revolution. But in the EU, the shared desire for law and order is so strong that the rest of the members are likely to support a member state in repressing such a revolution with essentially any degree of brutality, regardless of the condition of that state’s democracy, because the alternative (a successful coup in an EU member state) is impossible to contemplate.