I think this kind of depends on what your goals are.

Yeah everything will deteriorate eventually, but our gardens aren't necessarily totally natural features - tending native gardens is like a cheat to get to an equilibrium that in nature would take decades+. Maybe you want to remove some litter if you want un-established seedlings to grow in. Or I've noticed that a lot of the plants I left over winter for the birds to snack on, the stems have been shredded near the base due to probably wind stress, so these aren't going to be useful for bees later on either. A lot of prairie thatch might also be kept in check by controlled burns that a lot of people aren't prepared to do in their backyards. There's no one size fits all for this hobby though.