There is a lot of confusion regarding garment breathability, and even the best top level Gore Tex membranes on the market, will inevitably not "breathe" properly if the correct type of undergarments are not worn.
I am a road cyclist and know more than most the compatibility of under garments vs outer layers.
If you wear a light natural fibre base layer, (Enduro make Baa Baa for cycling) or something like Icebreaker, tight fitting next to your skin, with then a Polartec lightweight fleece, or a shirt etc, and then your outer fabric, you will notice a marked difference in the "breathability" of your waterproof garment, and give it the best chance to do what it says on the tin so to speak.
We often see people with a waterproof gore tex shooting coat, a nylon polo shirt, and a thick fleecy jumper or cheapo sweatshirt, complaining their jacket is not breathable and they wonder why after sweat has to fight its way through synthetic layers, and by then has cooled down and condensed inside the garment.
Wearing the right TYPE of clothing is crucial, regardless of how much you spend.