France has unions out the wazoo, yet you don’t see nearly the level of cost increases.
I wish they had different names because they are quite different.
In the US you are forced into a single union for an employer.
In Europe the union is for the employees, they have lots of employees from a wide variety of places, and they offer them services.
In the US the union is for the employer - they stand in between the employee and the employer and purport to decide what's best for the employee.
Oh, sure, they throw money in the pot for candidates, but in Europe, unions take actual political positions on important matters. They do not often get their way, but they act as an important counterweight in politics to the interests of the rich and powerful.
The answer is corruption. America is horribly corrupt, much like Latin American nations, and unlike western European nations. So unions in Europe actually work the way they're supposed to, whereas in America they're just another corrupt institution, probably much more corrupt in fact than most others, and cause more problems than they solve.
How do you get America to have unions like those in Europe? I have no idea, but I think it's like asking how you can turn Afghanistan into a country similar to Norway.
Easy. Allow the employee to pick the union - you can have more than one union per employer. Or no union at all if that's what the employee wants.
That's the only change needed.
If like, add a second change: It's not longer necessary to make an employer be a "union shop" any employer can have employees represented by unions, if that's what the employee wants.