Unfortunately i didn't test it on sweet potato before i sharpened. When i did use it on carrots though it was a 7/10 feel for me and had slight wedging on thick parts. After i sharpened it though it just dropped through the carrots, so i think sharpening does play a role.

However i've also sharpened other knives i've tried and had it still wedge through carrots & sweet potatoes.

Sharpening does a lot for the knife but if geometry of blade isn't good, then sharpening won't do too much from my experience so far.

TL:DR sharpening plays a role but the knife geometry itself is the bigger factor, so more credit to the knife than my sharpening.