No, glasses don't fix the shape of your eye, but they do correct for that uneven shape. I would know, because they've corrected my vision and it's now crystal clear after being blurry from astigmatism for years. It sounds to me like your prescription just isn't quite right, because you shouldn't have any issues if they had nailed it.

Don't get me wrong, I'm not dismissing that you have a problem, and I'm not defending Steam or saying they shouldn't have more accessible options for those with sight issues. What I'm saying is it really sounds like your glasses aren't where they need to be, and that's why you're having issues. With the tech they use to make lenses these days, you should definitely be able to dial in a prescription to get perfectly clear vision with astigmatism.