Ask HN: What Happened to Spec-Driven Development?

For a minute, it seemed like SDD tools like Kiro, OpenSpec/SpecKit, Tessl were gonna be the future of coding agents. It seemed like a good idea to me at least, and it resolved a lot of the issues people were having with coding agents kinda just going off and doing their own thing.

Nowadays though, it seems like all the SDD tools have kinda fallen off but all of the complaints remain—coding agents still improvise code that doesn’t fall under the user’s requirements all the time. Did we all just collectively decide that /plan mode was enough?