I don't disagree that systemic factors play a huge role, but individual actions can definitely contribute a lot as well. A family member of mine grew up dirt poor in a developing country but worked their ass off to save money to move to the US, worked their ass off more and is now in the top of their field, owns a house, multiple cars, paid for their kids college, etc. Luck almost certainly played a part (and choosing the right field to go into) and it's obviously the case that a lot of people who work hard all their life are never able to get out of poverty, but individual actions can definitely contribute to moving up the socioeconomic ladder. It certainly shouldn't be the only factor, though, as conservatives and the rich want it to be.
If it was, it might actually be useable