NASADEM total dataset size

I’ve recently started investigating NASADEM for some terrain visualisation tasks, and noticed that the total number of tiles on the Earthdata portal is way fewer than the global ASTER GDEM v003 dataset.

NASADEM – 14,520 granules
ASTER v003 – 22,912 granules

I’ve searched extensively but can’t find a definitive reason why there’s far fewer tiles in the NASADEM dataset. Does anyone know the answer? Both appear to be global coverage and both appear to be 1° x 1° tiles, so I can’t really account for the difference in tiles.

It sounds like NASADEM has an improved accuracy, but if there’s a lot of missing land data then I’d sooner stick with ASTER for my purposes I think, I just don’t want to overlook something obvious.