I am unsure of the context in which codabar was developed, but I know it was originally made for dot matrix printers, maybe if you go back to how those worked,

I am unsure of the context in which codabar was developed, but I know it was originally made for dot matrix printers, maybe if you go back to how those worked, it lended itself well to monospaced fonts because we had a fixed number of “dots” per byte cell. It can be roughly thought of like a low-resolution LED screen display used at transit stations to display real-time etas. The purposefully low resolution can save on costs while being able to show legible text - but not much else. Codabar was can be implemented as a font because the standard does not define specific start and stops symbols, instead it was developed as just a raw 1-to-1 encoding of character to pattern. It does not have check digits because it uses more space per symbol to handle error correction by making it very difficult to misread each pattern. The spacing (kerning) between each symbol is a different width ratio than the white bars found in each symbol. Going back to dot matrix, it does appear that some early printers just had a grid of character “cells” in which the spacing between each cell was slightly more than a single “dot”, this probably explains the codabar quirk with 3 different space ratios (black bar, white bar, and inter-character quiet-space) and probably is the beginning of some further investigation into that topic.