The reason to roll my own was: what I cannot create, I do not understand.
It has a cool backstory: travelling between stars at the speed of light using laers... it shows practical use of CLOS which is something I've always wanted to get into but never found the time... and it shows how ChatGPT can be very helpful to write tedious code (as someone who's written really tedious parsing, bit manipulation code, I will definitely look into using it for those cases).
Really recommended reading the whole thing for anyone just checking comments.
Also understanding for one is great and as a libertarian and conservative, yes. But real life not just individual. If one wor n in a group, understanding in a widely use langauage like Python may be important.
Key is not pure OR but and-and-sometimes-and-not.