Indeed the author has caught on that graphics is now much wider. Yet his post still focuses on the APIs. A bias he admits to.
APIs are the easy part of graphics programming. Now perhaps I say that out of bias, as I focus on shaders and artist work pipelines. The author focuses on APIs and thus reached for a simpler API as a teaching on ramp, while I would new learners run the other way and learn the basics of blender.
Learn blender, basic 3d modeling. Then dig into understanding how a model goes from disk, to cpu, to gpu. Understand what a draw call is, then batching in its many forms using a commercial engine. Once you know what everything should "look like" and what the state of the art is, only then reach for APIs and write a from scratch renderer.
If the learner has no idea about fultrusm culling, or triangle stripping, or instancing, or uniforms, or texture binding: a fresh from scratch c++ is a horrible learning experience.
Edit: When learning use either Unreal or Godot. You need source access. Time spent learning Unity is time lost. The author should not suggest unity is anyway equal for learners. Digging into the renderer requires breakpoints and source code.
I learned unity about 5 years ago and got burnt out on it after a few personal projects and a few freelance side gigs I took that used it. But I was not a decent programmer then and I have earned a CS degree in the time since. I actually used 3DS Max and Blender more than Unity but have since been distracted with web development and once I’m settled in my new job I am planning to write a raytracer. Any other recommendations?