the majority of missing moves are from gen 9 (plus some of the ultra beast signatures and other moves from gen 8 dlc). those pokémon aren't all coded either, hence the lack of the moves.
but dig? plenty of pokémon learn dig. not that it's a particularly useful move, as there is no 2-turn invulnerability, and /faint can be used anywhere, including in caves. use a reference site like bulbapedia to check who learns what and when. non-gen 8 pokémon use gen 7 data:
but dig? plenty of pokémon learn dig. not that it's a particularly useful move, as there is no 2-turn invulnerability, and /faint can be used anywhere, including in caves. use a reference site like bulbapedia to check who learns what and when. non-gen 8 pokémon use gen 7 data: