Right now the world is about 4 months old and it's already filled with abandoned places. Some of these places have been abandoned for several weeks or months even, and yet you can still find them there.
Those without a claim have lost anything of value, since the houses and containers decayed. So while they're useless to scavenging players, you can still find structures like ovens or kilns, and more annoyingly PAVING.
Ruins can be fun to explore when they still have houses and stuff inside, and some people even take them over as a new base. But the amount of ruins currently present makes the game look bad.
A new player running around right now would think the game is abandoned, even though the world is not very old!
To give you an example, in the area I'm exploring right now there's about 20 villages. Of those, 2 are active (growing crops), a few I can't really tell but have active claims, but the majority are abandoned with decayed claims. I haven't met a single player in weeks.
If the area was wilderness, I would just think it's an unsettled place and it would feel fine. But seeing all the remains of so many villages makes it really feel like the world is over a year old or, if I was a new player, the game abandoned.
In conclusion, once claims/villages no longer have authority, I believe everything should decay completely in about a week or two tops. That includes paved stone.
On a side note: dead crops (from winter) should decay too. Maybe leave them there for winter and spring, and then have them decay in summer?