MFW pickled things have expiry dates. Missing the point of pickling there buddy.

Quality of pickled foods can drop off over time. Plenty of fermented red sauces (colored red because of peppers or tomatoes) will turn brown over time from oxidation, which also dulls the flavors. Also, lots of pickled products are jarred still crisp but will degrade into mushy/soft textures over time.

Korean cooks have systems for how fresh kimchi should be for different dishes, as the fermentation continues even after putting it into jars. Newer kimchi is good as a dish on the table, older kimchi is good as an ingredient in stews or other things like that.

Hell, even wine keeps changing in the bottle, and can start tasting bad from being aged too long.

So there's still benefit in labeling dates, so that consumers can understand how time affects quality.