Did they? What's up with all the famine then? The empire relied on an obscene amount of grain shipments from North Africa and Egypt (plus sicily to begin with).
Roman food distribution was anything but efficient or fair
That was an economic issue - or at least perceived as such contemporarily. This is all second hand recollections so don't take me as an expert or anything. From what I recall of Revelations interpretation much of it was coded political satire like remarks about famine but plenty of wine. Essentially prolonged war harmed citizen-soldier farmers and there was a glut of slaves from their victory over Carthage. That meant the wealthy could benefit from buying up poorly maintained farms and they made more profit from growing grapes for wine than growing grain.
Inequality essentially lead to the famine indirectly. If the major buyers were the people enmasse wine would be less prioritized. Grain shipments would still happen given relative advantage in trade but it wouldn't have had such a dysfunction as food demand would have the proper 'clout'.
I recall hearing about one further irony later in history. One reform that made things even worse for equality was having state supplied armaments instead of citizens being expected to provide their own. It has long been essentially common sense and the way a military seems like it should work. One would think that would be better for equality by allowing rich and poor to fight and advance in status but it helped set up a proto-generalismo situation by having the power derived by the state instead of citizens.
Efficient doesn't mean perfect, or even free from flaws. In the ancient world, humans were very much at the mercy of the weather day to day, and one bad season could wipe out entire cities. Doesn't mean their farming practices weren't efficient for the time and available technology.
There is an argument that all famine is political, and has been for several centuries. It seems crazy on the surface, but it's hard to find counterexamples.
All of the worst famines are political, because the combination of political and natural factors push the death tolls beyond what nature itself is capable of.
Roman food distribution was anything but efficient or fair