I suspect that many gun fights in the US involve young people from underprivileged social backgrounds who don't know what they're doing. That demographic is much smaller in Germany as the welfare state keeps many of them on the right(ish) side of the law and the population is frankly older.

I believe violent criminals in Germany are more professional types. They know when they have lost and they will switch to damage control mode instead of escalating the situation. It's mostly organized crime as far as I can tell. Lawyers instead of gun fights.