Title correction: recovery of ozone layer makes planet safer against cancer.
The warming due to the ozone layer's recovery is a smaller problem than cancer, and cancer is a smaller problem than global warming due to emissions. (Because the emissions themselves increase cancer risks).
The ozone layer, if it never was harmed by mankind in the first place, would've helped us. Because it blocks UV light to an extent, and UV light causes damage to cells, including those of plants (which have a cooling effect due to taking up moisture from the air).