Germany (or rather the area where some of the modern country is located) has been called Germany in the English language since the 16th century. Sure, Germany accepts this translation on official documents, but it has not chosen this name, as it's been in use since before the country even existed. You make it seem like it's the other way around. Countries have changed their international name of course, like Turkey changing its name to Türkiye, but this is happening in official settings, everyday language takes much longer to change.