>If you have the resources (time, money, teachers etc.) to get your children the same education they would get in a (german) public school you might as well found a private one.

Unless Germany's public school education somehow doesn't show its results on tests like PISA then this shouldn't be too difficult to provide to one or two kids. More than that would make it way harder. And I'm sure that if you did try to found a private school you'd have to deal with a mile long list of inane regulations as seems standard in all aspects of Germany.

Just an example of the absurd regulations in a different subject: Germany requires a license to stream to more than 500 people and they've actually enforced this on streamers. The license can cost €10k.