Control Weather has not been able to clear the cloud cover. Wish might help, for a very short time. It's also possible that it won't help. The curse has blocked some divine powers, and disassembling it is the main challenge for the campaign.
In many areas, the Druids have been using Plant Growth to help compensate, but spell casting services cost money and not everyone can afford it. Some have taken to using it on undeveloped areas, to ensure that the local wildlife can make it, while others have actually refused, feeling that it's interfering with the natural order of things. (Remember, there are Neutral Evil Druids out there as well.)
But even if the spell was available for free, it only staves off the inevitable. Increasing yield by a third sounds good, until you realize that adding a third to nothing is still nothing.
We aren't at the "nothing" stage, and maybe we won't get there, but farmers can't afford to let any fields lie fallow any more, so the soil is being depleted by poor land management.
Cities are currently dipping into their reserves, the provisions set aside for bad years and long term sieges, but they won't last forever.
We have a modified version of the Magnificient Mansion spell, and that produces a lot of food. Even so, when you compare a spell that can feed hundreds to the needs of a city with tens of thousands, you're still spitting on a forest fire.
(Our version is a level lower, and rather than creating an unassailable extradimensional hidy-hole with an invisible entrance, it creates the structure in the real world.)
Create Food and Drink is even smaller scale.
One of the other premises of our game world is that the ranks of the high level casters have been decimated by the wars that have torn the old Roman Empire apart. The ones that are left are in hiding, knowing that the leaders will draft them into military service.
Now since the start of the campaign there have been people leveling up, of course, the PC's among them.
So let's consider what happens when the leader of one area or another that we visit realizes that we have a Druid with us who can cast Plant Growth several times a day. When they realize that the Bard can turn water into wine, or honey, or cheese (melted), or any other liquid foodstuff. When they realize that the casters in our group can summon foodstuffs enough to feed hundreds at a casting.
Yeah, it won't prevent the masses from starving, but it will ensure that the upper class will not only survive, but survive in comfort.
Will the PCs become victims of their own success? Hmm. Now there's a plot development. <evil grin>
(Note that my own PC is on the list now targeted for kidnapping and/or enslavement.)