I've lived in both Germany and currently Sweden. I have asked about the formal address here in Sweden, and the only time someone ever said you might use it is when talking to one of the royal family (while trying to suppress a laugh). Most younger people respond by saying that we don't have a formal-informal distinction here, which in practice is pretty true.
I have a good friend who spent half his childhood in Germany and then moved here (fluent in English, Deutsch, and Svenska). I asked about whether he would use formal or informal when visiting back home in Germany, or when talking to another German using German here in Sweden. Without hesitating, he said he always uses formal.
I have another German friend, who has been here only for about a year so far, of whom I asked the same: "Definitely I would use informal with any German here."
When I was in Germany, I could easily get away with using informal with anyone, because as clearly a foreigner with only moderate language skills, one can be forgiven many faux pas.
Interestingly, my spouse who is a fluent German speaker but also not native always falls into using formal address. She is quite often reprimanded for being too formal in situations that do not call for it. But that formal training was really rigorously applied, so she cannot help it. Even with our close friends sometimes.
W.r.t. my German-Swede friend, after we talked about it, he postulated that the reason he always defaults to formal is that he left Germany as a child, and so he never went through the transitory phase where children start to learn to talk to adults as equals.