Ambassadors cannot be arrested, sued, or taxed in the country where they are serving because of

Ambassadors cannot be arrested, sued, or taxed in the country where they are serving because of Diplomatic Immunity, because it's a legal immunity that gives to diplomats privileges and benefits to guarantee a secure passage and also it establishes that diplomats cannot be detained, demanded, or taxed in the host country. Moreover, that legal immunity has an inviolability character, where the diplomats benefits have to be respected by the country where they're serving.