I have no particular love affair with agile / scrum, but I think this take is rather juvenile...and frankly sounds like someone who is too emotional / unhinged.

First off, if we say "agile / scrum has failed" it begs the question, what should it get replaced with? Waterfall? Spec-driven development?

This discussion ultimately needs to face the fact that while spec-driven development was the gold standard for many years, it only worked because the solutions they were developing were software controlling formalized systems....

That is to say, in 1960 the software control system for the electricity power plant could be developed by using "software engineering" methods because the power plant itself was formally spec-ed and developed using engineering methods. The specific electrical components of the power plant had formalized input / outputs, so you could model that in software.

In 1970 your accounting system could be spec-driven because well....math itself is a formalized system.

As software started to push into more and more areas, it increasingly found that no specs could exist because there was no formalized system beneath it. A "chat network" cant really be spec-ed because at its core human communication isn't easily reduced to some formal system.

Scrum / Agile was a response to that and a decision to move away from spec-driven development and instead to break down deliverables into small bite-sized pieces so you could roll out something like "chat software" in distinct piecemeal phases.