Not to mention the US still hasn’t paid reparations for their genocide, and trump dismantled programs designed to clean up Vietnam era bombs and pollution that still kill people there, while China is partnering with them to build infrastructure. There’s still a lot of animosity over Chinas invasion though, they really should have sided with the Vietnamese over the Khmer Rouge, but they were trying to get closer to the US at that time, who also supported the Khmer Rouge.

There’s differences in the languages even written, for example in mandarin thank you is 感谢/谢谢 whereas in Cantonese it’s 多謝 or 唔該 depending on context. Cantonese also typically uses traditional characters rather than simplified. That second character up there in 多謝 is 谢 but in traditional rather than simplified. I’d imagine most research papers are going to be in simplified Chinese with mandarin phrasing, but learning traditional characters and going to simplified might be easier than learning simplified and then going to traditional.

20-30k is massively outside of the price range of many Americans, who rely on buying older used vehicles for sub $10k.

Mandarin is the most accessible and widely spoken, Cantonese is good if you want to spend a lot of time in the south. Good luck if you want to learn one of the hundreds of other dialects, maybe make a friend from one of the places and have them help you.