Revenue has remained flat across all four years, confirming the margin decline is entirely a cost story. Two lines stand out.

COGS has increased from 38% to 44% of revenue over the period, the single largest shift in the cost structure. This points to either significant commodity input cost inflation, rising spoilage and waste, or both. Given Goldcrest's reliance on ingredients like flour, butter, and eggs, commodity price movements alone could explain a meaningful portion of this increase.

Store labor has also grown from 22% to 26% of revenue, contributing an additional 4 points of cost pressure. Rent and overhead have remained stable, ruling them out as drivers.

Together COGS and labor account for the full 7-point margin decline. COGS is the larger and likely more urgent issue to investigate first given the magnitude of the shift.