No Swiss Italian

Generally speaking, Microsoft's language options are based on user demand. You can use the Feedback Hub to provide input to the developers regarding adding a new supported language. If you share the link created when you enter feedback, I am happy to upvote it for you as well. You can also share it with friends and/or via social media to get more people to upvote it.

Well you'd have to buy Swiss points. Buy the content with your Swiss profile and play it on your Spanish one.

swiss, colby, pepper jack ....

Just looked at that site.

Swiss edition only means that was the country the console was meant to be sold in.

My Swiss isn't the best (it's non existent) but it does look like it could be selling pre owned stuff.

When you buy a game you get the language that is available on that download

Very few games support multiple ingame language changing

Usually the nationally Supported languages of your region of your account

So my guess you are in Germany? Or swiss?

Games that have Italian would be ita in the description unless you are using the wrong marketplace like the us website rather then your console

Or ger for German content

Using the us website doesn't help it would be better to change the locale of the website to your account region to see the content based on your account region