It's not as simple as more CO2 = better plant growth. In fact it is likely the opposite for C3 plants. [0] Things like Corn, which uses C4 photosynthesis will hardly be affected by more CO2 in the atmosphere. I could go on and on, but this thread is the wrong place for this discussion.

[0]https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4036122/

https://science.gu.se/english/News/News_detail/increased-car...

https://www.nature.com/scitable/knowledge/library/effects-of...