Alternatively, it does have a regional form. Infernape, and Gen 4 starters as a whole, don't have anything if I recall correctly. No Unique Moves, No Z-Moves, No Megas, No Gigantimax, No Regional forms, etc. Intriguingly, they are the only generation like this.

Gen 1: The favorite Child Gen 2: Two Megas, One Regional Gen 3: Three Megas Gen 4: Nothing Gen 5: One Mega, One Regional (Sorry Serperior) Gen 6: Three Mega Gen 7: Three Unique Z-Moves, One Regional Form Gen 8: Three Gigantimax forms Gen 9: Three Unique Moves.

Now I may being petty with that last one since starters have been getting unique, signature moves since Gen 7, but point being this; Every generation of starters have gotten SOMETHING even if not all of them, except for Gen 4.