eSIM in an iPhone (country of purchase differs from the country of usage)

Hey there!

I am planning to buy an iPhone XR in the US (as it is cheaper), yet I am concerned about the usage of eSIM, as my primary country of residence is Germany. Are there any blockages, that will make my eSIM not function with German mobile providers?

A couple of years ago, I have heard that Apple Watch Series 3 with LTE purchased in the US would also only function in the US due to different frequencies of the eSIM? Not sure exactly what it was, but it would be great if you could give me some updated info on eSIM in the new iPhones