FX doesn’t matter when investing in stocks / stock funds, it’s not the currency that you’re investing in. Jeez, this q pops up so often enough that it’s annoying, maybe it should be in FAQ or school curriculums or something if they even teach financial literacy in school these days
It’s true that there’s a small markup to NAV*interbank rate, but 1) that’s not something that will “play for or against the investor and in the long term it averages itself” but should theoretically always be a positive cost, and 2) last time I checked, if you go for most liquid and highly traded ETFs and at a time when both markets are open, it’s actually very reasonable, certainly not your retail bank’s/travelex/some other shithole’s ripoff exchange rate that we’re talking about here. You can thank HFT and algotrading shops for this.
The bigger issue with non-US ETFs investing in US stocks is that you lose 15-30% dividend withholding taxes to US that you can’t reclaim later in your swiss tax return. At 2% div yield that’s basically equivalent to 0.30-0.60% TER increase
Another issue with non-US securities in general is sky high trading costs, 0.1% that’s not something you’d see on the US markets