Agree with the general point, but the nuance matters. Static-first approaches like static exports solve most of this — you get the DX of a JS framework without shipping a runtime to the client. The problem isn't JavaScript itself, it's shipping too much of it.
I use AGENTS.md daily for my personal AI setup. The biggest win is giving the agent project-specific context — things like deployment targets, coding conventions, and what not to do. Without it, the agent makes generic assumptions that waste time.
The iteration loop here is fascinating — having the AI see the physical output and adjust is something you can't get from just previewing SVGs on screen.