Wrt characters with "plain" features: If you're drawing a character with a few very distinctive features (say, "really big wild eyes"), then you have that to latch on to while drawing. As long as you get the unusual feature in the drawing, people will recognize which character you're going for.
But if you're drawing a character who has no quirky features then it's harder to feel like you've duplicated that specific character and are not drawing "just some generic person".