I remember playing around with setting up a Hackintosh, and found all those errors in the system logs --- then realised that an actual working Mac generates much the same (ignorable) errors.
To be fair to Apple here, so does every other operating system. Linux system logs are filled with errors too. In general, keeping the logs of even a moderately complex application "clean" - so that the only errors logged are real errors, in some poorly defined meaning of "real" - is very hard.
For operating systems it must be straight up impossible.
Mostly only due to misbehaving hardware. Something that should really not happen on a Mac. And "filled" is way hyperbolic, there usually isn't a lot of it.
