Ahhh ok I totally understand what you mean. Yea the edge cases are absolutely where you start to feel the pain and things look good on the surface until you dig in. I think even in the age of LLMs the adage of 90% of the time is spent of the last 10% will ring true.

Sure an app can be built and spun up in an afternoon, but are you willing to spend another 6 months ironing out all those little bugs, tuning it a bit, testing, tweaking, testing etc.