It definitely isn't. Irrational number ratios are impossible to manufacture.

You're just being contrarian. Obviously it is an approximation. Most figures are impossible to manufacture. There will always be tolerances. Let's say you produce two planks of wood, 2m and root 2m. Both are (+-0.1%) from their desired value. You wouldn't say the 2m plank wasn't 2m.

By what logic? Because I'd guess by the same logic, rational number ratios are also impossible to manufacture. Yet here I am, surrounded by parallel-ish edges. Measurement ≠ true length.