I've always loved learning new languages, I feel that learning new languages is a way to get insights into the culture that shaped the language. It's also a way to connect with the native speakers in a way that's more personal and natural than speaking a third common language.

I've always stayed away from Esperanto exactly because of those reasons. Because it's an artificial language that has not had a community large enough and existed for long enough, I feel there's little culture tied to the language. There's also very few native speakers so that also nixes the other reason for me to learn a language...

So, I'd rather learn Cantonese and Teochew than learn Esperanto. Even if I can almost always use a third common language (either English or Mandarin) to speak with native Cantonese and Teochew speakers. It's still worth it for the insight in the culture and for the connection one can get when trying to speak the other party's native language.