Our prices are largely influenced by the market price, which is currently at a high level. We hope to be able to offer better prices soon.

Prices in the USA are without tax.
Asus ist mostly more expensive than other brands

Cheapest 4070 Ti in DE and NL:
Germany €899 = Fr.887: Inno3D GeForce RTX 4070 Ti X3
Netherlands €929 = Fr.916: Gigabyte GeForce RTX 4070 Ti EAGLE OC 12G

ASUS TUF Gaming GeForce RTX 4070 Ti 12GB GDDR6X OC Edition:
DE: €1039 = Fr.1,024
NL: €1059 = Fr.1,044

must of the comments here are irelevant - Digitec does not show market pricing but dynamic pricing. It has nothing to do with taxes etc, just how much the customer is willing to pay ;)

So it is a number of reasons:

As already stated by others: taxes + customs, etc.

One that has not been mentioned here yet: Currency exchange
Since the companies trade in dollars they need to make a certain dollar revenue, they don't want to adjust pricing daily so usually what you do as a company is you pick an exchange rate in your favour (usually based on recent history), i.e. at the moment they could pick 1:1 as it was that briefly last year. then you will leave the sales price as is unless the exchange rate moves very far from your set point, for example 10%.

Hence why cards could very reasonably be: $800 = CHF800 then add taxes, customs, extra fees for operating in Switzerland, etc.
This explains why some cards are about CHF 880.
The cards higher than this are just AIBs that do not particularly care about selling in Switzerland and maintaining warranties here, hence they just bump up the pricing.
Even USA has this issue with certain AIBs not caring about their market and pricing higher.

My advice would be to not be fixed on products from 1 AIB like Asus and rather buy based on what is good value for money in this region (although in this case the 4070 ti is just terrible value in general).

The best thing is to buy a console and have saved a lot of money.