Plants are generally not CO2 limited. General water is the limit - thus deserts are not very green despite having as much CO2. Even in wet climate a few weeks without rain and the plants are going dormant.

In the ocean the limit is often other nutrients like iron. Attempts have been made to add iron to the ocean and those areas suddenly turned green (though it is not clear how sustainable this practice would be, nor if there might be other unknown negatives).

That isn't to say CO2 is never the limit. Large greenhouses often are CO2 limited (often burning fossil fuels indoors to provide the CO2 without opening windows and thus letting something else undesired in). There are no doubt areas where CO2 is the limit and so NASA can see more green that is attributed to more CO2 - but still CO2 is rarely the limiting factor.