As sawmill technology improved, they took the industry standard a 2x4 is anything between 1.5 and 2.5 thick + 3.5 and 4.5 wide and set all the tolerances at the extreme low end. This results in us getting perfectly uniform boards so the architects know exactly what they will do, and the sawmills get more useful boards out of the same tree.
Wrongo! That is not how they came to the designation of 2x4. The 2x4 is unfinished wood, 2 inches by 4 inches. It is smoothed in the milling process by shaving of about 1/4 inch from each face, creating finished lumber. Thus, a 2x4 is 1.5x3.5, and a 2x6 is 1.5x5.5 and a 4x8 is 3.5x7.5. And I didn't look it up on Wikipedia.
Nah. What you’re describing is the current process. The original version was green wood, which shrank as it dried, resulting in significant deviations in the finished lumber. I am glad you were able to resist the siren call of wikipedia, however. Good for you.