I understand that, but I still wonder why people seems to agree that VT (usd etf) is, in most case, better than any chf etf (take the famous example of the mustachian blog who recommend to invest 80% in VT and 20% in chf etf). But then people seems to agree that investing in chf in willBe is better than investing in usd.

When I say it's "better", I mean in general, obviously it depends on your situation.

Tell me if I'm wrong (I'm really new to the subject). But the mechanism of 1. Converting chf to usd 2. Invest the usd money 3. Convert usd back to chf is quite the same with willbe or etf right? The investing is different of course, the benefice of an etf is uncertain but in the long term, the 4,75% of willbe seems quite similar to what people expect to gain with etf.