Just a quick interjection to make a few points.

There are good and bad "breathable" waterproof garments and that relates to design, construction and materials.

I will respectfully remind everyone that "perfect" can be the enemy of "good" and having something with you like an inexpensive garbage bag or two, albeit imperfect, is better that nothing and can be, and has been, the difference between life and death.

Finally, WRT Gore-tex, I will note that all the high tech immersion/dry suits these days are constructed with Gore-tex and they are, indeed, completely waterproof when completely immersed or when sitting in a wet life raft for extended periods.