You just can't. And that's how it's supposed to work. Only a very small minority of the population can reach that kind of worth. It's the foundation of this system, no matter if the baselines grows, there will always be rich and poor.
There are plenty of places in the US where you can buy a house now - housing in the US overall is actually cheaper than it used to be per sqft as far as I recall. Then, in 30-40 years you may too be renting out a paid-off house.
The gist: If you didn't inherit, you are fkd in Germany.
MOST of wealthy people inherit it (and 2/3 of super wealthy inheritance in Germany is former Nazi money). It's unfair.
What helps me get by: I know my life is good, even though exiting the treadmill is most likely not possible. Enjoy what you have, invest a bit and focus on things that make you happy :)