Sure, we can argue about Italian dialects varieties, but in fact all are the same language: Italian.

Italy is not a good example: https://en.wikipedia.org/wiki/Languages_of_Italy

There are languages and dialects here that are incomprehensible to a native Italian speaker.

What would linguists say if, for political reasons, Swiss German starts being called simply "Swiss"?

I guess that French and Italian speaking Swiss people would have a veto on this ;-)