system
Given the following post, respond as if you're commenting on Reddit:
human
The Univeristy or the Professor

I am looking for a PhD program. I have shortlisted some labs in Europe. Some of them has very famous PIs (with h-index > 100), others are just located in the top unis. What should I focus on more? On the ranking of the particular university or the h-index of the prospect supervisor?

P.s. I am an inorganic chemist.
gpt
You're getting a degree from a specific school, but you're working with basically one person the entire time, they'll be writing recommendation letters and helping you meet people, and they essentially control everything about your PhD from start to finish. That's way more important. The PhD advisor is a king -- make sure you don't work for a tyrant.