I think you underestimate how many laws you need to keep a nation functional.
Even Hammurabi had 282 written laws and his was a ‘whatever the king says is illegal is illegal’ empire.
You need laws to cover everything from murder to product safety to child custody after divorce. And none of those are able to solved simply every time because many cases have a lot of nuance.
On top of that, as I said, you need a lot of rules covering courtroom procedures. Expecting a random citizen to understand things like when something can be presented as evidence and what sort of questions a witness can be asked is expecting too much of them.