[hotnfresh]

Bit packing/mapping et c. isn’t compression the way you’re thinking. What it is, is concise. It requires that the program know what each bit means, rather than telling the program what a value means (as a json structure might), so it shifts where meaning is assigned strictly to the program—a convention must be encoded in the program, not figured out at runtime, though technically you could turn this back into a form of config if you wanted, it just wouldn’t be jumbled up with your data—but it doesn’t really compress the data itself. It’s just efficient at representing it.

[edit] shorter version of the above: it stores the values, but doesn’t store what they mean.