"All the spices", save for tea, coffee, and sugar, which continued to be imported in quantity. And are addictive to boot.
A century or so later, laudenum.
The spice trade itself didn't shrink so much as it was subsumed by other trade, I think, particularly as shipping capacity, reliability, and safety increased.
My point being that 1) the UK continued to import luxury consumables and 2) probably maintained spice imports, though I don't have hard data.
If you have data to bring to the discussion I'd be interested in seeing it.
Sugar is included in what were termed spices, FWIW:
In the medieval and early modern periods, ‘spice’ was a term liberally applied to all kinds of exotic natural products from pepper to sugar, herbs to animal secretions.
From the sources I'm finding (relatively few and vague, granted), my interpretation is less that total trade in spices (however construed) fell in absolute tonnage than that the per-tonne value dropped as the goods fell in price and were consumed by far greater shares of the population. It wasn't that spices were less a part of culinary culture, but that because they were so common (both senses of the word) they became less significant. Total tonnage and likely overall value were all but certainly increasing, but the importance attached to formerly exotic goods (pepper, ginger, cinnamon, etc.) fell as anybody could attain these.
Look to the history of the pineapple (of which there were once temples built in its honor in Europe) from exotic to highly mundane fruit for another example:
A century or so later, laudenum.
The spice trade itself didn't shrink so much as it was subsumed by other trade, I think, particularly as shipping capacity, reliability, and safety increased.