In Finnish, we have a formal 'you', but it's kind of archaic and I there aren't really any situations where it should be used. In general, you should avoid formal speech. It's rarely used and sticks out, so instead of being polite it might even make you sound sarcastic.

Coming from that culture, German 'sie' felt awkward at first. It feels pointless, but at the same time quirks like this also make cultures more interesting. I remember this meme video where a guy insults a cop while addressing him with 'du', but as the cop turns towards him, he quickly corrects it with 'sie', making the insult 100 times better. That just wouldn't work here.

In English, I use it all the time because 'thou' has been dropped.