Is there a term for the gradual deterioration of quality?

You've seen this before: a new thing comes out, it's great, everyone loves it. But as time goes on the new thing is dialed back. It becomes a little smaller, it doesn't come with the same stuff, the stuff it does come with is cheaper, it costs a little more, until the thing really just isn't any good. I have in mind a rice bowl option at my workplace eatery, which used to be a gem, with veggies and toppings and sauces, but by degrees has become a scoop of overpriced chicken cubes on rice.

Is there a word that represents this kind of deterioration? "Decadence" captures the general trajectory, but it's the other way around, with things collapsing in on their own filigree instead of being trimmed down to generic mundanity.

via International Skeptics Forum http://bit.ly/2R9hpq8