Upward mobility still occurs in the US, at all levels. While the advice is difficult, almost impossible, for most to apply, it is sometimes applicable.

One of the main issues is that a lot of advice is presented as an unconditional, absolute guarantee to success. A college degree was never a guarantee of future success (contrary to great-grandparent's assertion), but the push to get everyone to get a college degree has rendered its utility as a helpful marker much more useless. Similarly, the ability to start your own business is difficult for most people, but even for poorer individuals, it is possible to start, say, a cleaning service with very little assets. (At the same time, such businesses are unlikely to make a whole lot of money at the end, but you might be able to move from working class to middle class, e.g.). A lot of contractor businesses--your plumbers and the like--are going to be from the lower middle class or middle class, and you can make some good money there, although that is also likely to be at the cost of your health much sooner than you expect.

> Upward mobility still occurs in the US, at all levels.

This is not a super relevant statement as it can be made with a single example - the rate of mobility is down relative to when those who'd give the advice experienced (which has been compounding for at least the last 30 years, some say since the 1970s).

According to one economist in 2020, in the U.S., absolute mobility, the chance a child earns more than their parents, has fallen from about 90% to roughly 50%. Source: https://www.economist.com/united-states/2020/05/16/two-leadi...

> the push to get everyone to get a college degree has rendered its utility as a helpful marker much more useless

Social segregation also plays a really important role too, and cross class relationships have plummeted - as someone who is doing well but didn't go to college, the relationship building in college is a factor that will work against me my entire life.

I would never say that upward mobility is impossible, or that its not worth it to strive for it. I am saying that dismissing headwinds due to no guarantee of success doesn't really take into account severely constrained actual access to opportunity that continues to become more constrained over time.