The point is that while good to remember, and specifically Fred Brook’s “No Silver Bullet” article about it, there are second order effects.
If coding becomes 100x cheaper, what’s going to happen next? At least to some degree, design and planning was there since coding is expensive. (Not just coding, debugging also got squashed by AI and was an expensive part of the job)
This is why the original comment seems pretty spot on, organizations will learn how to skip more phases, and startups are probably a place where this will be happening faster. (Not clearly though, a lot of big tech are happy tokenmaxxing to try and not stay behind those startups when they come)
If the cost of emitting syntax collapses without adequately resolving the essential complexity then you have not eliminated the design phase and you're just externalizing your failure modes onto downstream teams and systems.