my guy…
US citizens are obligated to enter the US on their US passport. They are also obligated to file taxes regardless of where they live. As a US citizen, you could be living on Mars for your whole life and still have to file US taxes.
You also have what, 6 years of back taxes to file? You should find a CPA with knowledge us US/German tax laws to prepare that for you. There may be treaties in place.
As someone else said, there’s also the selective service you were supposed to have registered for
I recently read about Ted Hall who shared nuclear secrets with the Soviet Union because he thought everyone should have equal access to nuclear weapons and this would prevent another world war.
Your logic is similar and it’s not a good thing.