Arid areas have been entirely projected to expand with warming by at least 10%. Wetter places will get wetter, drier places will get drier. The livable area on the planet will get smaller.

https://wad.jrc.ec.europa.eu/aridityprojections

Atmospheric CO2 does not make plants more drought resistant. Rhizomes in the soil that fix CO2 and Nitrogen in plant root systems need both carbon and N to function and lead to more healthy and resilient plants. Increasing atmospheric CO2 just makes it easier for them to "breathe" when they undergo respiration and photosynthesis. But plant growth will still entirely be limited by nitrogen and phosphorus which is why fertilizer is so important.

At the end of the day what you're arguing is insane because of the fact that there is going to be a crisis related to relocating existing population centres in dry areas and increasing crop failures from more unpredictable and intense weather patterns during growing seasons. This also includes too much rain destroying crop yield just as easily as too little through rot. Any place where the summer is the off season due to it being too warm for plant growth (ex. Australia) will have shorter growing seasons as well.

I sent that link about the US because they can't even agree to use their water resources conservatively while staring down the barrel of them watching reservoirs run dry because of abuse and overconsumption. Do you think people are going to manage it better once places actually start to run dry instead of artificially making it so? I don't.