I mean, the Yumi was a good bow for the purpose it was made for.
Most foot soldiers at that time couldn't afford mail armor, or full chain.
Full plate mail was absolutely alien and by the time Europeans could import them they already became obsolete to gunpowder weaponry.
Sengoku era tactics were usually tight formations and wave tactics, no personal shields, only emplaced ones.
But even after all that it was still only a "good" bow. Apparently it was hard to handle, sensitive to moisture and slow to make.
Another victim to the stagnation of technology due to hardline feudalism the Japanese were stuck for centuries, infighting.