"...if we simply distributed existing resources equitably to everyone"
There's nothing simple about distribution. It's at least as hard as producing stuff in the first place.
Solving distribution in a way that is both fair and economically sustainable has also proved to be extremely hard--much harder than just producing enough.
Despite the moral problems inherent to market-based pricing (the poor go to the back of the line), all the alternatives we've tried so far have led to far worse results.
The problem isn’t we haven’t solved how to make enough food to feed everyone, it’s that it’s not profitable to feed those that can’t pay for it.