there is a bridge you have to cross with art--where it has to be good enough to clearly hold the story. I think of it like holding water in a glass-the glass is your art, your story is the water. If your art is distracting or hard to read--then the story won't hold together, it'll leak all over the place. But if it's all art--that's just a glass with nothing to drink.
But the level you have to be at--while it's good, isn't necessarily in the refined finishing details. There's a lot of graphic design, a lot of storyboarding, and a lot of illustration that goes into comics. You have to be a jack of all trades, and it can be sort of intimidating. But, it's not necessarily about drawing perfectly. It isn't fine art hanging in a museum wall. (well...sometimes it is, but we'll ignore those times for this case)