Hey, Florian! I have already commented on your post concerning minimalism. I also heard a lot about Marie Kondo and her teaching people from all around the world (especially women) how to make their houses freer from stuff and their lives - from problems connected with the overabundance of that stuff.
To my opinion it's a great teaching and it is really worth trying. In the age of consumerism it is so important for people to realize and remember that the material things should not be the purpose and meaning of human life. Moreover, what's the point of attaching to them? When I sometimes catch myself thinking that I can't get rid of this or that stuff, I usually make a little effort and do this - just throw the things which I know I don't need or don't like any more, or give them to someone else. And then I usually feel free, it's an awesome feeling.
In this respect I really like the eastern culture with its philosophy.