I am a master's student in stem cell biology at one of the TUs in Germany. It's been one year of my program and my current grade average is 2.2 GPA almost equivalent to 75-80%. The thing is I am planning to apply to very competitive universities for PhD, such as ETH Zürich, TUM, etc. I am doing my best to gain more experience in the field I plan to work in my Ph.D. and even have good grades (1.0) (96-100%) in the subjects I like and want to pursue further. I want to know how much the grades matter overall for such competitive places. If I have enough motivation and experience in the field would it help to overlook the grade? What should I expect in terms of response from PIs in those universities?
I think that from an european perspective it is quite unimpressive (and even counter-productive) to focus so much on the unis being "top" unis.
To be considered for a PhD you have to show determination (like having good grades in the relevant subjects), to show capabilities (like having good grades in the fundamental subjects) and to know your inner motivations for a PhD.
Universities are not a conveyor belt to success, not even the top unis. Universities are just a toolbox to let you research what you want to research. Apply to the universities providing you good infrastructures and sufficient funds to travel to conference/workshops. Rankings and "perceived" top unis are just a picture of the past, focusing on them you may miss good opportunities from other universities that will be top unis in the 4 years of your PhD.
If you get into a PhD program by a "top uni" without an extremely strong personal motivation on the reasons that brought you there and how the top uni can contribute to your research, it is likely you will be psychologically squashed by all the bullshit and marketing crap coming from the pressure of the "top" status of the uni and nothing more.