I just googled “BASF T-Shirt” and immediately found the one he is wearing in this video (and he wear it in a couple of other videos recently)

All of scandinavia. There are public registers where you can look up the salary of everyone for norway, sweden and finland. When these registers were introduced, the salaries were normalized across the whole population

I actually had that conversation with my girlfriend this week. She does not watch any women on YouTube and I only occasionally do. Gabi Belle, Simone Giertz and Physics Girl are the only women I watched like ever