I think the root cause is dirt and salt buildup that isn't flushed due an overhang that protects from rain but not humidity (and not enough cleaning). So say these are cleaned more regularly - will they structurally hold up for many more years? Is there some kind of treatment that would help clean, protect, or disguise?
And if needing replacement, would the whole gigantic windows have to be replaced, or can you somehow stabilize the glass and unscrew the frame parts for replacement? The windows/sliding doors are on a high rise balcony, and function is more of a concern than looks. thanks