You're questioning the value of reverse-engineering things in general and publishing them on the internet or this specific reverse-engineering?
For me the basic value is just having more knowledge published in the open for anyone to read. I might not have any practical value of it, either ever or today, but I did learn a bunch reading it and I'm glad I did.
Not sure why you're downvoted because I think you ask a legitimate question.
To me, it's a combination of various things:
I've tried to outline the process I used so that other people can learn how to approach challenges like this. I learned how to develop software and how to reverse engineer by reading posts like this and watching talks from e.g. CCC or DEFCON. Hopefully I can give something back this way.
This might also be valuable to other people who want to virtualize macOS or iOS or those who do security research and run into these features while reading XNU code.
And then ofc I can finally flex in front of my friends with this because I was the first to pull of a new skate trick ;)
No right answer, just curious