The draw weight on modern yumi is very low, about 30 pounds (actually, 28 is standard for girls). The targets aren’t too far away, so it’s unnecessary to have a higher draw weight. There is (apparently) no reliable historical measurements of traditional yumi draw weights, so we can’t say what was normal for practical weapons in the past. I think it’s generally agreed upon that they were considerably weaker than their European counterparts (such as English longbows).