Lifespan is in seconds, not years. Greenland is old.
For all complex life and most of simple life, Greenland was there. It was in different places and depths, but those rocks were there for most of the time. There's only a few other places on the planet that rival Greenland's age (or more specifically, certain rock formations in Greenland, though they make up a significant portion of it).
Though one thing about "lifespan" is that it's intended to be "age at death", not "current age", so I'd call that an inaccuracy, as Greenland will probably continue to exist for billions more years (though when the glacial lakes eventually form and break free, there will be a lot of sudden erosion).
Makes me curious what the future lifespan will be for the various continents. I wish our own lifespans were more geologically significant. Though at least I got to see the time since dinosaurs tick from 65 million years ago to 66 million years ago.