That article was pretty complicated; I appreciate the historical understanding but frankly web legacy is too complex to bother with "why" too much, in the end so many things just don't make sense and are historical accidents.

Here's another take, just a short list of replacements. Interestingly, "&" is also escaped: https://pkg.go.dev/encoding/json#HTMLEscape

That's a helpful summary of what's necessary to make JSON safe to embed in script tags.

I agree the "why" is too long of a story, an accumulation of supposedly logical decisions that led up to the ball of quirks. It's too much to remember. Exactly the kind of thing that should be delegated to a specialized function made and maintained by experts.