And our shopping / delivery habits have changed.
(Cue Hovis music...)
When I were a lad the local corner shop would have two, maybe three big blocks of cheese which they would cut to order. They had a regular delivery from their supplier which could be predicted days if not weeks in advance. If it took three / four days for the delivery to get there, so be it, even for relatively perishable items.
The local corner supermarket now has over thirty varieties of cheese, each available grated, sliced, thick sliced and by the kilo in separate sealed pouches. the till reports to HQ "We've just sold one of our two packets of grated welsh goats cheese, send more" and the whole system relies on "just in time" ordering. Even if canals had the capacity to carry, they don't have the speed for our modern lifestyle.