The documentation is usually dog shit.
The corporate culture does not allow appropriate time for the documentation as it is considered something that cost money without a quantifiable gain.
It permeates in the FOSS space as well since writing good documentation is a skill and it is not fostered in corporations. So devs start great projects with terrible documentation.
You’ve used Windows for so long that you don’t remember how it was when you first started using it.
This isn’t different than what you are doing with Linux. The flow gets better and better and you will acquire the experience needed to navigate the issues. It takes time, that’s all.