That’s true for any software project - on average only 5% goes into developing of the first version, while 95% goes into continuous development, support, and maintenance.
A better solution would be first-class metaprogramming, like in Zig or LISP. Maybe with some subset which guarantees to halt (I.e. no unbounded loops, no recursion, no FFI, known input size, hard time limits, etc.)
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