Know the single most critical separation between Capitalism and Socialism? Answer: It has to do with who controls production (farms, manufacturing, housing, energy, transportation and etc.). Capitalism features private/citizen control; Socialism features government control by politicians who know nothing about production. That is precisely why Socialism has never worked. Look at Cuba, Venezuela, Russia or the much more complicated brand of socialism in the E.U. (a developing "failed state" in its own right).
Couple the overt failings of past/existing Socialist states with a subject that is never discussed by the Left, and you have . . .
a nondescript political philosophy.
And that subject is . . . . who gets to profit from ownership/production; those who run the State or the investors and owners within the business community? Under no circumstance, is there serious and populous "upward mobility" for "the masses" within a socialized State. I mean, if the State keeps the profits, not you the worker bee, how do you move up in the world? The answer is obvious, don't you think?
In summary, upward mobility is impossible in a Socialist State, but clearly a reality in an private ownership State.
Now you know.