I learned Mandarin almost 30 years ago and other than being able to order in some of the restaurants and follow along with “Crouching Tiger – Hidden Dragon” without most of the English subtitles it’s done me no (economic) good whatsoever.
There are reasons why English is the dominant language of business and other languages like French and Japanese aren’t. Verbalized Chinese has an extremely limited number of syllables, so to “produce” new vocabulary they either have to adopt it outright from another language (“sofa” is an example), or string a bunch of existing characters together. The chinese word for “thermostat” is 5 characters long.
It’s not like learning Mandarin would make you an insider there. A native would still be able to slip into their home dialect if they didn’t want you listening in and there are literally dozens of those in regular use.
Spoken Mandarin is more pleasant for me to listen to than Cantonese or Hakka or Vietnamese or Japanese, but I’m sure that’s just a personal preference. In my ear, spoken Mandarin tends to be more melodic and moderately paced – there’s a lot less tendency to slur or mumble because the tones are so much more distinct. Not as distinct as what you’d hear at the operas but still pretty clear.
I would advocate learning Mandarin if you or your kids were considering living there or doing a LOT of business there. Otherwise, I think Spanish is still going to have more application here in the U.S. Much easier to learn, too (similar linguistic and cultural roots). The overseas Chinese will invariably assimilate and learn English. Not every group shares that priority.
