Stroke Order in Chinese Writing - How reliable is 笔顺？

https://www.youtube.com/shorts/SLuYryJQ6iw

In this video I ask an uncomfortable question. Are the rules of 笔顺 universally reliable? In this video you get the answer by examining to basic and almost identical characters: The character 力 li4, meaning power, force and 九 meaning "nine". Common and frequent they may be, but they are far from ordinary. For starters, the character 九 is listed under the radical 丿， which already makes no sense. We are baffled to discover that the strokes of both characters are written in a different order, quite the opposite of what one would expect.