He doesn't have nothing though? He currently has Beatrice, unseen hand, and cor Leonis in the novels.
If your talking about s1. Well that's kinda the point. S1 Subaru is kinda a piece of shit before Rem's speech.
Even then he didn't really need any powers s1 when he finally got his head out of his ass. He helped defeat the Witch Cult and the white whale cause he learned the power of swallowing his pride and being diplomatic.
Without that he wouldn't of been able to convince Crusch to mobilize her army, or gotten Julius's help against betelguese.
S1 Subaru getting a power up would kinda miss the point of s1. Cause Subaru was a prideful piece of shit that took Emilia's kindness for granted and thought that he could do everything himself.
Him getting an actual power would simply validate that behavior.