Because the value of things is decided by consumers, the value is independent of the cost of production, and for that reason is a lie that the difference between value and cost is the labor.
If labor were worth the difference between product value and cost, it would not be justified to produce anything, because at the end of day, nothing would be won by working. It only makes sense to work if the final product is more valuable than what was spent, including labor.
Because value is relative to other valued things.
Resources are limited, so what you spend on "essential services" cannot be spent on other things.
Healthcare is "essential", but if you spend 100% of resources in healthcare, it will never be enough. You can spend billions to keep alive a person more minutes, and he will die anyways, but society would lose all housing, all food, all clothing, and would be miserable, so healthcare doesn't had infinite value.
If you find any "essential services" too expensive, is because you need other things more important, like having food or a house.
If the state pays for "free" healthcare, it has no limit to spending, and you cannot more get a house, food, clothing, or anything else.
That's why "essential services" have a price, like anything else, and should be restricted to be profitable.
Profit means that the value produced is higher than the cost, because the cost are other things that you need more.
Profit-seeking is the epitome of selfishness that can only be justified through twisted ideologies. When applied to governments that are supposed to take the least and give the most, it is pure evil, just skimming off goods and services someone desperately needs to put that in your pocket.