German universities aren't very good at attracting foreign students and they tend to underperform in international rankings (in large part due to the previous point). I don't think German universoties are an example anyone wants to follow.
With regards to attracting international students, the effect of English being the language of academia cannot be overstated. If you compare Germany with countries like France, Spain, Italy, Russia, Japan or South-Korea, I would rather doubt that it attracts significantly less foreign students.
I don't doubt that German Universities are very very good. But learning German is a very big added cost for most prospective students in the world.