Let's just consider what a decade in a landfill will do to a hard drive.
It's not just a big pile of trash you could rummage through, according to the site manager
things that were sent to landfill three or four months ago could be three to five feet deep
So there is a good deal of waste on top eleven years later, which means
- the layers get compacted, things break, under the weight and pressure of heavy machinery crisscrossing the site.
- other waste gradually dissolves into who knows what kinds of chemicals. I can't tell what kinds of waste exactly is deposited there, but clearly electronic parts among others.
We're talking about a hard drive that was removed from the computer, so it only has a thin aluminium casing for protection. Chances are it's crushed beyond recoverability.
Also, in 2013, this would have been a mechanical drive. Even in optimal circumstances, there are a bunch of ways they can fail, leading to data loss.
The spinning disk inside the casing is fairly fragile. One scratch on its surface could render it unreadable, as would, say, spilling a sugary drink into it, which our unfortunate bitcoiner already did. Now imagine the drive buried in an environment full of debris and potentially corrosive chemicals.
TL;DR — At this point, even if a major excavation was undertaken and the drive was located, there is barely a chance that any data would be retrievable from it.
It's dead, Jim. Bitcoin man is chasing a dream long past its sell-by date.