My impression of Germany is that it’s mostly just full of Germans with a smattering of Turks. Like Berlin is apparently 88% white

I think you're looking at Berlin, Connecticut lol, the first thing that shows up when you google it

Germany doesn't have any official statistics on race. It's actually illegal to collect that there. But if you've been to Berlin there's no way could think it's 90% white, it's probably around 50-60% (which is more diverse than most of Germany of course)

Germany is about 85% German

I think that statistic is saying 85% of Germans are German born rather than talking about ethnicity. Like, ~15% of people in Germany are foreign born immigrants at the moment. That's the same number for America actually. 23% of Germany's population are immigrants or children of immigrants, so there's no way 85% of Germany is ethnically German.

Also, where you are matters a lot. Major cities on the coasts are far more ethnically diverse than the center of the country.

The same applies to European countries as well. European countries are smaller but pretty densely populated: take a 40 min car ride within Germany, France, wherever, and you can go from a super diverse area to a very white one. I am American btw.

Religion Maybe? Germany has 1-2 million more Muslims than the US, but very few Jews

Yeah that's why I said "in some ways," Islam is way more prevalent in Germany (5.5% vs 1.1%) and most of Europe but Judaism definitely isn't (0.15% vs 1.7%)

I'm not at all disagreeing the US is largely far more diverse, I'm just saying Germany has a good degree of diversity as well, and if you've ever been there there's no way you would say it's virtually absent of diversity aside from Turks. Implying "Germany isn't racist because not many of them interact with people of color on a daily basis" just isn't true, one because Germany does have racism problems (although probably better than most parts of Europe), two because poc are still everywhere

Was Germany overwhelmingly ethnically German for a few decades post-WWII? Definitely, diversity is a relatively new thing to Europe in general, especially with genocides of the past. But that's been changing pretty fast in the past few decades, especially since the early 2000's, so I don't think it's fair to say they're extremely white today. Hell the US was 87% white in 1980, 80% white in 1990, 75% in 2000, etc., and honestly that's probably where a lot of European countries are at the moment

Seriously, if you've ever been to Germany there's no way you'd be talking about it like it's virtually an ethnostate. On the other hand, a lot of Eastern European countries are basically ethnostates, and they tend to be far more ultranationalist and xenophobic than more diverse European countries. That's because diversity and exposure to minorities usually breeds tolerance, not the opposite. Poland and Hungary and modern sundown towns in the US are incredibly racist because people there don't see and interact with poc on a daily basis, so I also don't get the assumption that Germany theoretically not being racist would be due to it theoretically being incredibly white