That is precisely the strength of Hit Points and its weakness. Most games which have some specific wound mechanics end up in death-spirals: you take wounds that reduce your fighting capacity which in turn makes your far more likely to sustain additional wounds while less likely to inflict your own wounds. In some games, that is a perfectly valid style of play. Those games tend to not be combat-focused. But D&D is absolutely a dungeon-delver and it is built on the principle that you will fight more often than you don't, and for that the simplicity of HP and "the only hp that matters is your last" makes the game faster and easier.