Did I somehow skip an important page to read, regarding development on Roku? I seem to be missing basic concepts...
Ha! I wish it was as simple. And your humility is appreciated 8-)
No, it's just you have to acquire that knowledge face-planting a few times in Roku world. I have been around things-Roku for like what, 5 years? So i was reading the APIs since the time they were bound in PDF files and have long-term observations over their evolution.
The SG was newly hatched to the public last year and an attempt at "SDK 2.0" pivot - but the documentation was edited in place as if SG is coherent with everything else existing before, which it isn't. Whoever is writing that "couldn't see the forest for the trees" - likely for being too close so unable to see the big picture.