We're into an interesting, semi-philosophical issue here. In mathematical terms, all sorts of objects are, to all intents and purposes, impossible to represent on small scales. Think of the thickness of the plating on a gun tub. Or the lines in a guardrail. Or the grid on lots of radar screens. Or, for that matter, the plating that forms the sides of an open bridge. In fact, most of the things routinely represented by photo-etched metal are, in literal terms, over-scale - sometimes by quite a lot.
When photo-etched parts came on the scene, back in the late seventies or thereabouts, the modern warship modeling community seemed to accept that such parts made models more attractive and realistic. (I personally think they were right.) Up till then, the usual approach was "if you were far enough away from it that it looked that little, you wouldn't see it." (That one always struck me as a cop out.) Surely we've all seen enough beautifully executed models on 1/700 and 1/350 scale to be convinced that, in the hands of a good modeler, various features of a warship can be represented convincingly on those scales - even though the representations are, strictly speaking, out of scale. I've gotten to the point where I almost expect a 1/700 model by a good modeler to have guardrails and rigging. But if somebody wanted to take the position "if I can't show it to scale, I won't show it at all," I'd have trouble arguing. To each his/her own.
I haven't built enough modern warships to have a firm opinion about rigging materials. I've stretched a whole lot of sprue in my day, and it looks fine until it gets busted (which can happen very easily). I bought a spool of EZ Line some time back; I haven't had a chance to try it yet, but it looks like great stuff. I also have some examples of very, very fine fly tying silk, which also looks promising. And many years ago a friend gave me a spool of nichrome wire that he'd bought at a military surplus store. Its diameter is .0025 - pretty daggone fine. I've used it with, I think, success in sailing ship models (it makes great ratlines). Its problem is that, though it's not likely to snap under normal handling, it is likely to kink - and when that happens, getting the kink out is almost impossible. I have a 1/700 battleship on the back burner, and I intend to use a mixture of all those materials to rig it.
I also have a copy of a fine book called Building Model Warships that was published back in the mid-seventies, when the 1/700 "Waterline Series" was getting established. The book asserts that radar screens and guard rails are "impossible to model" on 1/700 scale. When I read that sentence, and then glance at the catalog of Gold Medal Models or White Ensign Models, I wonder: What will the hobby look like 35 years from now? I wonder what the next development in rigging material will be.