I felt that learning any language is useful. If nothing else, learning a new language keeps your mind sharp, opens you up to new cultures and ideas, allows you to experience the world from a different perspective.
As for learning Chinese, well, I’m not aware that there is hype for learning Chinese. I don’t recommend Chinese languages to casual learners. Mostly because the Chinese language is harder for English speakers compared to other languages from Germanic and Romance language groups.
For example, an English speaker could reach conversational proficiency in Spanish with a couple of years of casual learning and practice, but the same effort will not get them to the same place with Chinese. And if you live in the US or Europe, learning Spanish or French would be much more useful in everyday life than learning Chinese.
Learning Chinese, to the point where you can actually use the language (either for reading Chinese content on the internet, watching Chinese entertainment, or visiting China), requires a serious commitment. It’s not something you can spend 15 minutes every day on Duolingo and get some instant results.
So is it really useful to learn Chinese? I think it is useful. But it requires serious commitment and effort to learn.