After using Linux regularly for a couple years, I did a Linux From Scratch build just for fun. I found it a really good way to learn all of the key pieces of Linux and understand a little bit better how they all work together.
The way it’s setup, you get a choice to just copy paste commands and learn very little, or read the details and learn a bit more.
I never really used it for anything other than education. Keeping it up to date and secure is almost prohibitively complicated, but I learned a lot from the process. I just looked at the project for the first time in a long time. It looks like they now have a section to track security vulnerabilities along with suggested changes to address them. Perhaps it could be viable as a distro, but I have no desire to go through the whole process again to try.