That's (IMO) too narrow view of what a "machine" is. Complex machinery of any kind never is 100% correct and needs constant correction and maintenance. I still think approaching this as a "calculator" is awkward at best.
Computers are extremely close to 100%, we generally expect a CPU to never make errors even after years of working. If it starts making any errors at all we throw it away and make a new one.
We must work in extremely different industries!
My computer will pretty much add 1+1 correctly forever never making a mistake.
My computer will perform an 'error' every time I put bad code into it, and some of those logic chains and error conditions are not very obvious.
The issue here is you think the LLM is performing a category 1 error, when the problem we are seeing is a much more human like category 2 error.