Even in Germany you can work around it. It's necessary for a third gender option, or when the gender is not known.

I imagine that it's not France either? French has similar greetings, with the same indecisiveness around the polite/casual pronouns. There's the added challenge of Quebec where casual pronouns are far more commonly used.

There's also the trap of "mademoiselle" which is no longer used because we no longer care about a woman's marital status. It's the same as with Fraulein.

You are right that rules might need to be made by country. The beauty of small scale solutions is that you can sweat small things like this instead of applying Silicon Valley sensibilities to the entire world.