It's just a display of power that can't be used for everyone or it would break the system.

Oddly enough, this issue was anticipated in Matthew 20:1-16

I would negotiate differently with the landowner if he offered to hire me again. Sure, he can do what he wants with his own money, but he’s now shown he's willing to pay a denarius for an hour of work.

And, since it's a parable about salvation, does that mean that you'd also try to negotiate a life of sin with a conversion to virtue somewhere in your 60s or 70s?

I don't base my behavior on an expectation of forgiveness from "daddy in the sky". And I pay more to people who work longer.
The final straw that drove me out of the church was being told that a death row conversion, if truly heartfelt, was sufficient to go to heaven. Any system that allows murderer and victim to share the eternal reward is flawed.

Or designed from a point of view we can't even imagine. But that's mostly true about religion: if you look at the whole system from a day-to-day point of view, it doesn't make much sense.