Guido isn't a functional programmer. He doesn't know the trade off. The benefits of functional programming are less technical debt and greater modularity and l

Guido isn't a functional programmer. He doesn't know the trade off. The benefits of functional programming are less technical debt and greater modularity and less bugs. The cost is less readability and less efficiency. Reduce is ultimately the most readable way to iterate and accumulate with FP. The only other way would be recursion which is less readable.