Kissinger noted in Diplomacy (1994) that Germany's key role in European history has been main defender of Central Europe against Russia. And ofc, Russia was a major foe in the last wars. To me, there's no way Germany missed the point of Russian moves the past decade.
So assume for a moment that they knew this day was coming.
If they have energy independence, they might also be called to task to play their traditional role and their natural role now as the powerhouse of the EU and NATO, to lead the fight against Russia.
But if they're hobbled by energy dependence, they can shrug and say "sorry, it's simply not a feasible option for us. We're sitting this one out." Which seems to be what they have done.
Add they get cover from their domestic green problems as well. Alles ist gut.