I think that in general, expecting a 'career for life' with one company, as was common in the 1950s, is a bit naive today. Companies change, needs change, people change, just because you like the job now doesn't mean you will in ten years. To give a tech industry example, right now you could be working for a cool startup, in a few years the startup gets acquired by a large tech company, they change the management style, it's not fun anymore. Like imagine you got hired at Github around 2010, would you definitely still be there today? Or even in 2020?

Also, you have plenty of people who will have career plans like "work in finance in NYC for 5-10 years, amass a fat pile of cash, and retire to a small farm in the middle of nowhere". If I were living in China or India, I might see "spending 5-10 years in the US earning large piles of money and returning to my homeland to retire and live a life of leisure" as a valid career path.