There are some/many pretty ordinary sparkling reds, too sweet, too light in mouth feel, too young and simple, occasionally too dry or disjointed dosage, don't remember sour as a problem, but many cheap ones are just carbonated, next level tank fermented, best are bottle fermented.
But the best are a joy to drink, complex flavours with older components, full mid-palate, long fresh finish, generally preferable to a similarly priced Champagne or sparkling white for my tastes.
Each to their own, I drink sparkling reds at least once a week all year round, more often in the warmer months.