When plants remove CO2 and release O2, they have to do something with that carbon atom. They can use it to make sap or fruit, but mostly they use it to build more plant.
A plant that isn't growing, like, a LOT, can't possibly be removing much CO2.
A plant that isn't growing, like, a LOT, can't possibly be removing much CO2.
This only clicked for me when I started wondering why you never have to refill the soil for a houseplant even when it grows.