[samus]

The official written language is German, albeit a different standard than non-Swiss German. The difference is not that big, it's like between written American and British English. But I can assure you that most non-Swiss German speakers can't casually understand Swiss German dialects.

Edit: these dialect are commonly used in court, public offices, and often on TV. They have a vastly stronger role in public life than in other German-speaking countries.

[angrais]

That's dialects though. The same could be said for most regions in the UK from people living in the UK or abroad, e.g., a Scouse understanding a Glaswegian. This is similar in Italia across regions.

[kuboble]

They are dialects. Swiss German isn't a language but a group of dialects, but they aren't closer to high German than Czech is to Polish.

I think my point stands that it's a distinct language from the official one. It definitely feels like that in practice where a lot swiss people feel like they have to wear their official hat when speaking regular German and they prefer to have casual beer conversation in English rather than high German.