> therefore making it a more valuable language to acquire for business, diplomacy and travel

Learning a Chinese language for the business, diplomacy or travel opportunities is a stupid, stupid idea. In the English-speaking West, bwtween 1.6% and 5.0% of the population are native speakers of both some Chinese language and English. The business and diplomacy opportunities that require a Chinese-speaker all go to these people*.

Nobody's going to hire some rando to speak Mandarin when it's equally easy to hire a person who's as good as the natives, and got to spend the 3 years of effort one needs to learn Mandarin on picking up some other useful business skill.

Travel opportunities are not great, either: normally, you can visit the PRC for 15 days, you're railroaded throughout your whole trip, and you're required by law to stay in a select few hotels where the staff speak English anyway. If you're looking to learn a language for the tourism opportunities, you're much better served by learning Spanish, Russian, or for that matter Japanese, which allow you to visit a lot more otherwise hard-to-access destinations.

* You have a slight edge if you also speak some obscure language in a country with few English-speakers who nonetheless want to trade with China. There are very few such countries. All of Africa is out (English and French have very high penetration), as is South East Asia (Chinese itself has a high penetration), as is the Arab world: a few Eastern European countries such as Hungary might qualify, but guess what, Hungary also has a sufficient number of native Chinese speakers to saturate the demand in that niche market.*