For clarification for non-Swiss people: Grades in Switzerland go 1-6, with 6 being the best, 4 being passing and 1 being the worst grade. A 4.75, typically rounded to a 5, is therefore a decent, though not amazing grade.

For ETH it's getting close to amazing, as you'll pretty much never reach a 6.

Depends. At least for EE there's a big difference between the courses that are supposed to filter the students (usually years 1 and 2) and those that don't. For the latter a high grade like 5.75 or even 6 was doable, for the former the time limit and amount of material to study is so harsh that I wouldn't even know where to start to achieve that.

The undergraduate courses in Theoretical physics at the ETH are done with books (e.g. Goldstein: Classical Mechanics, Jackson: Eletrodynamics...) which are PhD Level in the US.

I think that is true for most German speaking universities. I know for a fact that both Unis in Munich and Heidelberg basically teach PhD level courses in Undergrad in the sense that there is no Graduate Electrodynamics and Undergraduate Electrodynsmics just one experimental and one theoretical course in which Jackson is typically one of the references, the same is true for QM etc

That's why ETH is among the top ten universities in the world.

Physics study at ETH is notoriously hard, but that’s not what you get at CS AFAIK.

Could you enlighten me on something? Do you know why the grading scale has more failing grades than passing?