Sadly enough, Arlington cemetery is full to overcrowded. In truth, it should have been limited to Civil War dead, with other, unique sites used for other major conflicts.
Likewise, there should eventually be a recognition of “ashes to ashes, and dust to dust”, that nothing remains of the human remains, and instead of leaving headstones to weather to just rocks, that they be moved inside, to preserve their information in much less area, and that the ground be reused.
This has long been the tradition where cemetery land was at a premium, in many cases, graves being reused when just bones remained. The bones were then cleaned and put in an ossuary chapel. Few Americans have ever been in such a chapel, and while at first they are repelled by the idea, they soon realize that it has a much more sacred character than a common building.
I live about a mile outside of Arlington Cemetery. It has not reached “capacity” yet. My firm belief is that the Pentagon would shut down Fort Meyer and tear down every structure on the military reservation....to eventually enlarge the cemetery onto those grounds. I would agree that it probably should have been closed to more after WW II....with another major cemetery established in the region.