You could argue that the reticence to add features to your service due to the the sheer complexity, time commitment, or flat out unwillingness to not upset the apple cart is a sign of age.

I personally doubt age has much to do with it. Consider Windows - how old is it now? MS are adding crazy new features on top now more than ever.

I would argue it doesn't have much to do with age, but rather with market dominance. If you are the top dog you don't need to fight for users by implementing various features.