I built up my drawing-skills before I started a comic - but that's not because I felt like I needed to be a good artist. It just took me a while to realise that comics were a thing I could do (dim, I know! XD).
Some of the best comics I've read have had "bad" art - and by "bad", I mean that the style is not one that people think of when they think of good art. It has shaky lines, or weirdly proportioned people, or no solid perspective on the buildings, or whatever - but it's used to serve the story. The shaky lines become part of the storytelling, and so on. While I adore fantastic artwork in a comic, there are times when fantastic art can get in the way of the story; sometimes, what a story needs is a shaky, badly drawn character, to get the feeling across.
And no - great art can, for me, never make up for a bad story. It can make up for a mediocre story, but it can't ever make up for a bad one - the same way all the glossy special effects in the world can't save a bad movie.
My advice to you is to just start drawing your own comic. You're never going to get better as an artist unless you draw, and comics are a perfect opportunity to do so!