Socialism is left/liberal as a concept (and so is capitalism, in actual fact)... It's not left/liberal when implemented at scale...

The arbiter of resources, whatever or whoever that may be, invariably becomes right/authoritarian. The simple nature of the arbitration causes it, and a truly left/liberal society would, by necessity, require a lack of said arbitration.

Such a society cannot exist at scale. History has proven that repeatedly. A left/liberal society could arguably only exist as anarchy, and frankly, capitalism is far closer to that than communism is. The "every man for himself" nature of capitalism is inherently more capable of providing individual liberty and equal opportunity than the "to each according to his needs", very simply because of the inherent requirement of having an entity judge that need... Said judging entity is inherently authoritarian in nature...