Capitalism versus Socialism is a cop-out debate. No one has the genius or prescience to predict their outcomes without far more context and a lot of luck. The greatest minds of the past three centuries have come down on both sides. Social media chatter is not going to improve upon Malthus, Mill, Carlyle, Marx & Engels, Dickens, Marshall, Fisher, Keynes, Von Mises & Hayek, Polanyi, Samuelson, Arrow, and Sen. We must infer that this is not a helpful question.
Keynes was probably right that the principal political challenge of humankind was to simultaneously solve three problems: economic efficiency, social justice, and individual freedom.
What we know for certain is this:
1) Unfettered capitalism must fail. The most intelligent advocates for Capitalism say so and say precisely why. And it does fail — in many cases vast majorities are impoverished while tiny minorities flourish -- leading to what Polyanyi referred to ironically as "a stark utopia." Further, “one dollar, one vote” is inconsistent with sustainable democracy. Finally, unfettered capitalism is not only unjust, it is inefficient — despite widespread confusion about this.
2) Regulated capitalism or social democracy can in (deep) theory work — but policy makers and regulators must be honest and be protected by herculean meta/regulations against "capture" (the idea advanced, sometimes disingenuously, by "public choice" economists. If political agents can be prevented from exploiting their power badly, Keynes’ three challenges might be met better than in the unfettered brand of capitalism
3) Socialism or central planning can also work in theory — again, it has a chance whereas unfettered capitalism must get it wrong — but in this case the challenges of preventing abuses of political power are even greater than in social democracies in which democratic pressures are typically stronger. All three goals might be met, but most historical experiments with socialism (and its right wing cousin, fascism) saw individual liberty crushed. It is prudent to be wary.
4) Theocracies assume away the importance of efficiency, justice and liberty — and, not surprisingly, do very badly against those metrics. But for those singing from those hymnals, sanctifying the law may work.
5) Communism — the closest human beings can get to “the soul of the white ant” (a collective identity that deeply satisfies the Clan impulse) — can fall prey to a particularly pernicious form of inequality of voice — dissent gets treated much the way it does in theocracies (as heresy) -- and in practice can be inefficient, lacking in liberty, and still unjust.
6) In ALL cases, the failures devolve from inequality in power and voice, whether those failures originate in inequalities of wealth or political access. There are plenty of OTHER problems with each, but a rational way to design a system that succeeds at promoting efficiency, justice and liberty is to build in safeguards against significant inequalities in incomes, wealth, opportunities, and political voice — including the vote, the power of dissent, diversity of representation.
Of course, the protection of the minority from the majority (even when all vote freely) is also important and only well addressed by the brilliant design of certain types of Constitutions (like the American Constitution) — those that define and defend the inalienable rights of all (albeit imperfectly if the writers wish to sustain the power of some over others).
To paraphrase Bill Clinton (who got it wrong), “It’s POWER, stupid.”
In any form of government, we fail if we fail to safeguard the weak from the strong. Fighting about “socialism” may be a social-media gimmick, but it is not worthy of our attention.
The Romans said to ask: cui bono? (Who benefits?) If you wish to contribute to a discussion of comparative political systems, this is the question you must ask: is unequal power being leveraged and, if so, how can we protect the weak and restore a balance of power? Ethics 101 says moral action enhances the dignity of all human beings: does your policy meet this requirement?
As Benjamin Martin (the "Swamp Fox") advises his young sons in the film Patriot -- aim small, miss small. The big critiques (Socialism is bad! Capitalism is cruel!) aim at the side of the barn and miss by a wide mark. Keep the discussions narrow and precise enough to hope to get close to saying something useful.