Also, funding for research might be increasing significantly, but it's starting at low levels. In addition, funding for education in Germany is way below the OECD average [1], in 2017 Germany spent only 4.2% of its GDP on education compared to e.g. 6.7% in Norway or 6.2% in the USA.
It is also quite difficult to find a tenured position in academia in Germany. You are expected to change the institution you work at several times during your career - for many "Juniorprofessur" positions (equivalent to assistant professor), there is no tenure track, so you have spend a lot of time to apply for a tenured position at another institution during the six years (this is the upper limit) of your employment as Juniorprofessor instead of spending that time on research and teaching.
As a PhD student in CS, the situation is rather good, however. The competition for the best students with industry results in PhD students usually having a 100% paid position (TV-L E13 pay grade, ca. 4000 Eur gross/month, see [2]). However, I have regularly heard recommendations to come to Germany as a PhD students but to leave as soon as you got your PhD... also, in other areas of science (e.g. biology), it is common to only have a 50% or 25% paid position as a PhD student (but you're expected to work full-time nevertheless, of course).
[1] https://de.statista.com/infografik/15423/bildungsausgaben-ge...
[2] https://oeffentlicher-dienst.info/c/t/rechner/tv-l/west?id=t...
