Russian is another great gateway language because it unlocks the Cyrillic and Slavic worlds.
Italian then completes the picture, as it has many similarities with Spanish, French, and rare Latin-roots languages like Lithuanian.
I used to travel around Europe with my university friends. One knew Italian, another one Russian, I knew German. It’s quite interesting how you can get around most places in Europe with these languages, and consume a lot of culture.
Of course, everyone speaks English these days. But it’s a richer experience to travel when you understand what the people say and can read the signs, etc.
I recommend trying German and I can’t imagine how most people would still apologize about their Deutsch skills 10 years in — the language is really easy. Of course, the article author mentions perfectionism, which is a separate topic.