I am surprised it took until now for an advanced Western nation like Switzerland to do so.
https://www.bbc.com/news/world-europe-58696604
“Some 64% supported the measure, making it one of the last countries in western Europe to legalise same-sex marriage.”
“Over the last 20 years, most countries in western Europe have recognised same-sex marriage. However, in Switzerland many big decisions go to a nationwide ballot, and this can slow down major changes to social legislation. The new law, which had the backing of the Swiss government and all major political parties except the People’s Party, was passed by parliament in December. However, it was then challenged by opponents, who gathered enough signatures to force a referendum.”
Mike's Maxims 