Do businesses click their fingers and make profit? No, in the game world it's done with Profession points, and the occasional dice roll.
Consider the "trade consortium" you mention. They would invest in a ship, either to hire or to buy outright. Possibly several ships, as that improves the chance of all their ships getting through. Then they'd invest in a captain with the skill and experience to navigate the harsh storms around the Cape of Good Hope, and the long voyage. (i.e. not a 3rd level Commoner, or even a 3rd level Expert.) Then they hire a crew and buy provisions for them. Then they'd invest in a cargo, and hope that they'd picked goods they could sell profitably in the Far East.
Then they cross their fingers, hold their breaths and wait three years. Maybe four. Maybe forever, as not all ships completed that voyage.
Alternately, they invest in a few cargo devices, such as Portable Holes, and a higher level spell caster. Then they invest in a cargo, albeit smaller than a ship would carry.
Then they wait a few days.
After a week the spell caster is back, along with the master trader that went with him, and they reap their profits. (Higher gross profit margin because no product was lost in transit.)
Then they take what they've learned about marketable cargo, perhaps fill some custom orders, and send the spell caster off again. With more accurate assessment of the demand, and without having to invest in more magical containers, the net profit goes up this cycle.
Now we compare the net profit from 50 cycles of the spell caster with one cycle of the ship. (And that's presuming one trip per month.)
The cycle speed can be accelerated if the spell caster is hired simply for transit, and isn't required to stick around while things are bought and sold at each end. Even using
Teleport (not even the Greater variety), you could speed that up to 150 times around v once with the ship. And that multiplies the profit. Bump to
Greater Teleport and you could transit several times a day.
You see, this is a lesson that modern retailers understand (at least, the successful ones): The profit you can make on any individual item or line of product isn't as important as one might think. What matters is how much profit you can make with that,
per day. The faster you can turn your money, profitably, the better.
The trade group could start with a smaller capital investment (one or two cargo items, a trade representative and a porter, plus the spell caster's services, plus trade goods ) and turn their money in a few days time.
Smaller risk, easier to arrange, quicker turnover and a higher percentage of goods arriving safely? Much bigger profits.
And as the profits accumulate, maybe they invest in more Portable Holes, to multiply their cargo capacity. Each is a one time investment, and all their other costs are fixed.
Question: Do you know how many trips the Polo brothers made, and the impact those trips made on the world?
And yet, you continue to argue that this sort of thing isn't a "game changer".
But you must be right because, like I said, you win the discussion.
Now, back to my original topic: Presuming a worldwide event or condition that caused a decade+ of declining food production, what impact would you see it having on the game world?
What good plot or story hooks could we develop from this?