No, they don't. Businesses just send their negative data to the Schufa.
I worked in that area for years, and unless you're actively trying to tank your score, the Schufa is almost useless for all sides, and maybe businesses only use them to filter the really bad cases.
More than a surface level understanding is not necessary. The level of detail in the meme is sufficient for 99,9% of jobs.
No, that's not all just accounting, it's pretty much everyone who isn't working on very low level libraries.
What in turn is important for all sorts of things is knowing how irrelevant most things are for most cases. Bit level is not important, if you're operating 20 layers above it, just as business logic details are not important if you're optimizing a general math library.