Perhaps if the parable were a real business the vineyard owner would have this trouble, but the reason for that is scarcity. Labor is scarce, vineyards are scarce, grapes are scarce, and money *should be* scarce.

Even so, it’s important to view the parable through the lens of salvation rather than taking it literally. Scarcity itself is a result of the fall (Genesis 3:17) so we should keep it in mind that God’s economics are not necessarily the same as human economics.

God’s salvation is not a scarce good. My salvation does not take away from yours, which removes any legitimate concern about how I came to acquire my salvation. The lifelong Christian should be happy, not jealous, of the deathbed convert.

I think the parable makes more sense if you don’t view it through the lens of scarcity in the economic sense as rules of scarcity don’t apply to a superabundant good like God’s salvation.