Why can't someone who mows lawns for a living not make enough money for a simple life?
This is a good example, actually. In the limit, the activity of mowing a lawn does not generate enough production of real wealth to fund its own existence.
Specifically, I mean this: the increased production of food, tools, etc. from the landscaped lawn combined with the reduction in costs of dealing with rodents, bugs, difficulty of travel, etc. you'd have if the lawn wasn't landscaped is not enough to pay a person "well" for that landscaping.
Now, you might argue that people may be willing to pay a landscaper excessively to maintain an image, etc. This may be possible for a time, but if you're paying them more than their efforts generate, you're going to deplete your savings and eventually have an issue.
But this example also shows an artifact of the political methods of assigning people wealth in conflicting ways: "the landscaper should only get paid based on the economic value they directly produce" but "property owners should be compensated for people using their land, even though property owners don't necessarily do any direct work." Or said slightly differently: risking capital is physically different than performing labor, but many systems don't account for those differences.