I don't want to sift through docs and man pages and debug cryptic compiler and runtime errors in my spare time.
There are far richer things for me to do with my life.
I want to use my computer to get my tasks done and be done with it. Slogging through technical details an LLM could crush in minutes is a much better use of my resources.
Also I don't want to take someone's existing project and change it. They have too much cruft and don't work Just The Way I Like It.
That's why we create custom stuff from scratch.