In many ways, vigilantism helped build higher societies. No tribe emerged from the primordial aether with bureaucratized and abstracted concepts of legality and ethics which in any way resembled high civilizations.

Vigilantism was one of the costs "priced in" by social codes. If you screwed a man hard enough, he might just come for you. You can see this reflected in folk wisdom such as "nothing more dangerous than a man with nothing to lose". That cute little adage isn't saying "oh, those with nothing on the line try harder", it's warning that once someone has no chips left on the game board, they might flip the table.

History is replete with this echo: "surrender with honor", "allowing an exit", "chose to retire", etc. In our very safe, very insulated, very civilized world, these might seem quant or be accepted as received moral precepts, but they are based on a firm inherited calculus: every man, no matter how reasonable, has a point where he'll turn to tooth and claw, if only to make you bleed with him.

We might think of our age as one built on these costs, but so managed that we no longer pay them. Unjust words no longer result in duels, but we say slander is bad. The shopkeeper no longer has to beat thieves, because the justice system punishes theft. And the tribe doesn't have to mob-justice the degenerate who wrecked the common green, because social shame makes the idea of transgressing abhorrent, well before the thought of violence arises.

Or rather... our society was functional. For a blip of time in the late modernity, the West managed to reach an amazing peak. We'd priced in vigilantism to our social systems so efficiently that the vigilantism was no longer ever actioned. Unfortunately, over time this lead to virtuous violence being classed as mere violence, and morally equal to unjust violence. Like many modern ills, this wasn't felt at first, as the moral inertia of the old system propelled behavior that was no longer incentivized by the current market. Slowly, though, new actors came about in an age with new incentives, and they better adapted to their environment.

If a powerful CEO can get ahead with profit maximization through legal murder, and the only penalty is a fractional hit on a rocketing upward graph? Why not? The only external cost is some disapproval from people he doesn't care about. He's optimized for his environment, because he's recognized that the formerly "priced in" vigilantism behind that disapproval has been replaced with a memory of said vigilantism, like a vestigial clause in a defunct contract.

We've been at this point for some time. The grinding inhumanity of our era would have brought our ancestors to violence long before. We've constrained this through the anti-agentic "all violence is (equally) bad" propaganda.

So yes, this murder, and moreover, the general public acceptance, is indicative of social degeneration. But it's not a descent from normality. It's a return. A ball was thrown into the air, and for a time (the late twentieth and early twenty first centuries) it seemed to hang suspended at its apex, but it has now begun to fall.

The proper response is to recognize where we are, what we are, the historical anomaly we are exiting, and decide how to proceed.