If you use a compiled language, you should periodically look at Godbolt and see what your code is doing and what changes to your code will do in the compiled output.
In this case a positively insane way of calculating squares and cubes generates 311 lines of ARM assembler output that will swallow your memory. With even something as simple as -O1 on the command line it’s replaced by one or two multiplications respectively. With -fwhole-program it removes the functions entirely and interlaces them into the loop in main().
Know your tools. It makes huge differences!
Eh. Honestly, I think what you’re saying, and the points the article is making, are pretty valid. That’s still gonna be way, way overshadowed by the absolutely ridiculous example they chose to use to make their point. Like “Since you’re writing code that’s ridiculous to such a degree that it wouldn’t even occur to most people that the way you’re doing it would even work, you better turn optimizations on, so the compiler can fix your code back to normalcy behind the scenes for you.”