Carbon monoxide gas is more dangerous than carbon dioxide gas. Why?

(N/A) $CO$ and $CO_{2}$ gases are released by the burning of various types of fuel. Carbon monoxide is poisonous,whereas carbon dioxide is not poisonous in its nature.
Carbon monoxide reacts with hemoglobin in the blood to produce a carboxyhemoglobin complex. This complex is about $300$ times more stable than the oxygen-hemoglobin complex (oxyhemoglobin).
Carboxyhemoglobin,even at a concentration of $3-4 \%$,significantly reduces the oxygen-carrying capacity of the blood.
This oxygen deficiency leads to symptoms such as headaches,weak eyesight,nervousness,and cardiovascular disorders. Due to the increase in its proportion in the blood,the death rate is high. In contrast,carbon dioxide is non-poisonous,although its high concentration in the atmosphere is harmful due to the greenhouse effect.