Just a few weeks ago I helped dig up and relocate several time capsules. These are short term ones, they were all buried / will be opened within 10 years - but in just that short of a timeframe, there was worry that the place we buried them would soon become inaccessible.

Even at that, it took more than a year after learning about it for anyone to bother recovering them, even though plenty of people know where they are and all you need is one regular shovel. They aren't really anyone's top priority. And why should they be? The whole point is for them to be forgotten. If you already know what's in there, you don't really need to keep a physical capsule at all.