> Such mobility is not as common in Germany or Italy, for example (I keep bringing up Germany because I lived there for 4 years). In Germany you tend to get boxed into your career fairly early and after that you kind of just coast to the end of your life.
I'm sorry to say it, but the actual data disagrees with you.
> You don't see aggressive job switching to try to get the highest salary and you don't see 40 year old Germans deciding they want to go to dental school like you do in America (for example). In Germany your future career is pretty much set by your mid-20s depending on how you did in school/exams.
You only see those things in already upper-middle or upper class environments in the US. An amazon warehouse worker doesn't aggressively switch jobs to maximize salary. They suffer in a shitty job because they need to to survive.
If you ignore the existence of the least economically mobile when discussing class mobility, of course you'll see greater than average class mobility. There are more working and lower class people in the US than upper-middle class people, and those people have less mobility than their European counterparts, and data on social and economic mobility backs this up. Stop wearing rose-colored glasses and looking only at the social mobility of your peers. Look at everyone, and look at data.
> Sure you do - there is an entire generation of middle class people in America who started off lower middle class in the 80s and retired millionaires in the 2010s thanks to investments, promotions, increased education, real estate, etc.
I don't think that's true. There are some, perhaps, but what you're claiming is that there's an entire generation of blue and pink-collar workers who retired with six-figure incomes. That's not true.