It’s called Communism, it fails every time. Liberals still want it.
In my efforts at getting through to those rare liberals who are still capable of honest and rational thought, I have found that throwing them the bone of showing them where their nonsensical feel-good ideas actually work, and then showing them why they don't work. Communism is one of my best approaches.
To rebut your point, Communism DOES work. It works every day, in every culture, and in every part of human history. "From each according their ability, to each according to their need." This is what every family has done since the dawn of civilization. Usually, one parent works, and earns the income for the entire family. From him, because he has the ability. Let's say one child is in their teens, and is working a little bit. Their needs are smaller than the special needs child, and also different than the baby, and also different from the non-working parent (if there is one)... but the parent(s) provide and dole out all, "each according to their need"... and the system WORKS... very well in most cases. Communism does work... at the FAMILY level.
It is when people try to force this system onto a larger scale that it falls apart... EVERY TIME... and it falls apart primarily because of Human Nature, most especially Love. I love my children, far more than I love the children of some couple in Dover Delaware. I'm sorry, I just do. I want more for them than I had, and most others have. Communism tells me that this is wrong, and I must be forced to work equally hard for both... and so of course, I work less hard, because it does not get me or my closest loved ones appreciably ahead. The economy tanks... because of Love. You, my dear Liberal friends, cannot possibly want to promote a system where Love is an enemy to its success, can you??
(We won't even get into the rampant and unavoidable fraud and cronyism inherent in national Communism.)
Anyway, I sometimes get some traction and flickering of light bulbs above their heads with that approach. YMMV