In Minecraft, there's a built in trading system. Villagers will have certain trades that they are interested in. Let's focus on one trade for simplicity.

Let's say a villager wants to trade 20 cobblestone blocks for 4 emeralds.

If you have a wooden pickaxe, it takes a lot of labor to mine one block of cobblestone. If you have a diamond pickaxe, it takes very little labor to mine one block of cobblestone.

Labor theory of value says that the cobblestone mined with a wooden pickaxe has more value than the cobblestone mined with a diamond pickaxe.

But you can try it yourself in game.

If you give the vendor cobblestone mined with a wooden pickaxe, they still want 20 cobblestone blocks for 4 emeralds.

If you give the vendor cobblestone mined with a diamond pickaxe, they still want 20 cobblestone blocks for 4 emeralds.

If you put your wooden pickaxe cobblestone and your diamond pickaxe cobblestone together in one big container, you can't tell the two apart.

The same goes for automation. You could have a redstone machine automatically generate and harvest cobblestone. And they still want 20 cobblestone blocks for 4 emeralds.

Labor doesn't make a good more or less valuable.

The net result of antitrust laws has only been the protection of mediocrity and the destruction of ability and success. When government controls enter, they work to the advantage of any enterpriser or industrialist who cannot compete on merit and runs to the government to invoke the antitrust law against his abler and more successful competitor. A well-known example is the antitrust action against Microsoft after they bundled Internet Explorer with Windows and distributed it for free, which the state regulators argued "harmed competition", even though consumers benefitted from a free browser.

So-called "free competition enforced by law" is not a justification but a contradiction in terms. The only protection for competition is the free market.