Another fact that is conveniently ignored is that CO2 is FOOD for plants, and not poisonous.
Oxygen, in large quantities, is toxic and destructive.
Most of the ‘air’ you breathe is made of Nitrogen. Oxygen is only about 20% of what we breathe.
... also I should add.
If anything, we need to limit the amount of oxygen in the air. Just a little bit TOO much and BOOM !!!!!!!!!! We could actually set the SKY on FIRE.