Depends on the store I'd wager. We have a store here (Ametller Origen) that sell things they cultivate/make themselves "nearby" (in the same region, and among other things they sell too) and sell in their own retail stores, I'm guessing most of their customers do indeed follow the habits of seasonality as lots of stuff isn't available outside of the seasons.
Strawberries are available year round - we get them from Morocco and Spain outside the summer. They do taste differently and during the off season are less reliably red all over.
Thus I will buy them only in the Summer.
Prices also change over the year.
They're so large, watery, and tasteless, that I grow them myself or go without.
A lot of foods are no longer seasonal, as noted above, but I can't say I can taste the difference. Except for tomatoes and strawberries where I think I can - who knows, maybe I'm imagining it?
Strawberries again I never partically liked even home grown ones. Som modern ones are tasteless especially those available out of season.