People used to make decisions by drawing straws or interpreting bird flights or animal intestines. Now while this appears to be a very silly way of making a decision, and it certainly where we have reasons that will make our chances of success better, we don't have access to use that decision-making procedure. This is a famous paper on how magic, religion and science compare (not necessary to my argument, but it's an interesting paper if you've got the time).

Basically, it's pretty advantageous to turn to magic as a way of making sense of our chaotic environments. Why? It's a mental trick. The placebo effect is amazing. It helps us act confidently, which increases our chance of success in our unpredictable environment, even if our reasoning is not ultimately (in a grand sense) the most sound. In very many ways, society recognizes this and rewards confidence.

So, in many situations - where our ability to predict the future is low anyway - superstitions are perfectly acceptable ways of dealing with unpredictability because they help us act confidently, which helps us confront that unpredictability. If you don't believe in a particular superstition, then of course it'll be silly to you. It doesn't have enough cultural-symbolic resonance for you to make sense. But for other people, it helps, and so long as an decision-making apparatus is not robustly superior (e.g. modern surgery > alternative medicine), then we shouldn't judge the superstitions of others too harshly.

If you can agree with that alteration, then perhaps your view might be "when we have a robustly superior decision-making procedure, we should use it in preference to alternatives, but when uncertainty is high superstitions may be useful aids to navigate environmental unpredictability."