In Western Europe you can find every political side represented, from far right nationalists to actual socialists.

Yes, and Germany (likely) will have had the same Chancellor for 20 years. That's some choice you've got there.

Parties ≠ diversity.

Universal healthcare is present in almost every country in the Union and isn't a topic of routine debate.

"We don't debate things that you do" is not evidence of diversity; it's the opposite. In the US we have states that have banned capital punishment for 100 years longer than you have, and other states which still have it. That's diversity. You're confusing diversity with conformity.

Everybody has a voice unlike the US which doesn't have a true left wing.

This isn't the 19th century. Stop pretending that Europe is the center of civilization and that if our left-wing doesn't conform to its standards, it's not "a true left wing." In China, the right-wing is communist and the left-wing is capitalist. In our country too, the left wing is different from yours. It's still left wing. Stop de-legitimizing everyone else's politics to make yourself feel superior.