For whatever reason, there are 4* fully evolved Ground type Pokémon that don’t learn Stone Edge: Seismitoad, Toedscruel, Sandy Shocks and… Excadrill. Seismitoad can live without it, it had (at least in SwSh) a pretty colorful move pool and Stone Edge wasn’t ever really used. Toedscruel very obviously based off of stats doesn’t need it, but more options aren’t bad. Same with Shocks, which wouldn’t use it but could with its useable base 81 attack stat. Excadrill, however, has been dealing with Rock Slide’s fairly weak base power of 75 for 4 generations now, for no discernible reason. It wouldn’t necessarily kill for Stone Edge, but the move’s 25 base power increase as well as heightened critical hit chance could really make a difference, in spite of a 10% accuracy reduction. It’s a discrepancy that will always bother me.
*Not including Wormadam Sandy Cloak, Arceus Ground and Silvally Ground.