This is kinda bad faith as the overwhelming bulk of statistical and economic literature on the matter makes it clear how terribly expensive incarceration is.

Execution does end the money drain BUT our method of doing so necessarily makes it stupid expensive.

The best thing we could do for the thing the person is raging about is stop the for profit incarceration system, remove the death penalty entirely and work on a reform system.

Yes and No.

I agree completely in a fallible system these executions ought never exist.

However creating a framework of rules with outcomes and holding all accountable to them is the most morally / ethically benign thing we do as humans.

The state is the only ethical executor of these decisions.

BUT the system is fallible and made up of fallible people and isn’t always steered for the moral / ethical and as such your last sentence is even more truthful than even you meant it.