I've never been able to understand people with good audio systems and presumably good ears who have NOT heard cables going through break-in. Every cable I've had, especially power cords, goes through an almost predictable sequence of initially being anemic with hashy bright highs, no bass, no dynamics and very limited fine detail or nuance, to a state of normal sound. Usually it takes 10-50 hours, with fine detail and chromatic nuance being a late stage. If somehow you are not hearing this, then either your system is not revealing, your cables are zip cord, or something else is going on. I'm a pure scientist/engineer type and I've got no problem with this. If you're hearing different results, I'd be interested in knowing. There's certainly no religion in it.
And of course you shouldn't spend $2000 or anything else on cables until you hear them and decide that they make enough difference in your system to be worth it to you. But do take some time to listen. Or make your own...it's more fun.