It's completely fine to be uninformed, still learning, or even uninterested. But writing bold, naïve statements instead of asking questions does not contribute anything.

You could have written: "Why do we need to reduce CO2 if plants thrive on it?". Then, someone might have invested a bit of time and effort in you and the audience to share their knowledge.

That is disingenuous and misleading - some species of plants can use more available CO2 but not all can (there are other limiting factors in many cases as I understand it), but for sure most plants will be far, far more affected by the extremely significant negative effects of climate change than the small positive contribution of extra CO2 for photosynthesis.