So like... nyeh
by what metric?
The US as a whole might be more diverse than a single EU country, but it will depend a lot on your metric for diversity.
The difference between states is big but you go on to say that it's as big as the difference between two European countries. Your comparison only points out Europe is as least as diverse as the US and still has a significantly higher life expectancy.
Are you seriously to claim that the EU is a single country? Or that there are no differences between EU countries? That link actually has a table of all EU countries, and it ranges from 72 to 83. This is actually a LARGER difference than in the US: where it ranges from 74 to 82.
You need to read what's actually being said before climbing up the walls.
This matters because when you look at these crude aggregate stats, people naively assume that it means that everything is a bit worse but the actual American story is usually more like broad prosperity with some truly awful outcomes for anyone who falls through the (very wide) cracks.