Works fine in your alternate universe but not in the canon universe, which is what we are discussing.
The problem is, unless we assume that all non-self-sufficient worlds have tiny popuolations-- under a few million for all of human space the canon universe cannot, full stop, end of argument, work. The entire system is based on limited FTL transport with no real way to increase it until well after the Jihad. The Mule is listed as one of hte most common dropships and it carries about 8144 tons of cargo.
That is...tiny compared to even small cargo carriers in actual service, most of which mass over 50,000 DWT (many, such as the Maersk Triple E container ships Mass a lot more -the Triple E can carry up to 18,000 TEUS).
Okay, so to simplify things, I'm going to go with the traditional 4ish pounds of food that every person eats per day. So, a world with 1 million people, needs four million pounds of food per day!
4,000,000/2000=2000 tons per day.
Okay, not so bad, about 1/4th of a mule's cargo load.
Now let's multiply it by 365: 730,000 tons of food per year.-- over 89 dedicated mule trips per year.
And that's the bare minimum, if someone misses a flight we starve, level of shipments. For one world. one world with 1,000,000 people.
IF the world was important, and on a major trade route and NO house lord EVER diverted shipments, it might be doable.
But a world with one billion people?
1,000,000,000x4, 4,000,000,000/2000=2,000,000/8144=245.5 Mule equivelant shipments.
Per day. 27 of the largest civilian jumpships ever built would be required for every day, so you'd actually be talking hundreds of jumpships and thousands of dropships that would have to be always in motion.
Save for a few tiny worlds that also have something very important on them, there is no way any world in Btech can be dependent on food shipments.
And this really runs into problems because as late as the Jihad series, you had Buenos Aires which stated: "Buenos Aire’s food found its way to 25 billion customers on six
diff erent worlds—no more."
But even if we assume that you're only talking a pound a day, that's, 12,500,000 TONS of food shipping per day. If you drop it to one ounce of food stuffs per day (and note that the food was specifically described as things like grain and meat), thats still over 781,000 tons of food.
Per day.
Now you can drop it lower-- but at that point, Buenos Aire's is no longer a food exporter, but a world that occassionally sends a few shiploads out-- certainly not a world that anyone would talk about having 25 billion customers for food.