> 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.