I agree with you that if conditions are completely dry - then it's better to not wear a waterproof membrane. It really depends on the conditions. Everything is a trade off - waterproofing vs breathability is a prime example. But the comprise provided by quality membranes are worth it for most people. Hunting in Montana where I grew up, Alaska hunts or the Kentucky I've lived a few years now there is a often a heavy morning dew, a creek crossing, swamp, bottom or whatever. It's extremely rarely on a hunt that am I better off with a full waterproof boot (IE Muck boots) or rarely does it make sense to hunt without a membrane.
All manufacturers of waterproof membranes define "waterproof" by a minimum rating. Each one varies in this rating but a rating above 20-30k mm more or less means that under all but the most extreme conditions you'll stay dry. A membrane rating is defined by 3 metrics for breathability & waterproofing. By definition a "membrane" is a selective barrier so if a garment is truly 100% impermeable (IE rubber boot) it literally isn't a membrane. A membrane does 3 things - it resists water from the exterior, it allows water vapor to travel out from the interior & it allows air to pass through (CFM exchange).
It quite literally isn't true that waterproof (as defined by not getting wet) & breathable membrane doesn't exist. The US Army has done extensive testing on it (I'll locate & link) & it's well known/tested. With quality membranes I can seal my mouth against from the inside and exhale forcing a limited amount air through it through it. A PVC, rubber or laminate cannot do this. In fact some membranes actually increase in breathability with temperature.
In my opinion - most people dissatisfied with a breathable boot often are using a leather boot with a liner. You treat the leather with waterproofing where you are adding another layer & limiting breathability. Add insulation in on that & you're probably not really "breathing" at all by the time air & vapor has to pass through all 3. A quality well designed boot is key & the materials have to work together. My synthetic Salewa boots can get me through a wet area for extensive time while still being comfortable for miles & miles when dry. Rarely do I ever take my boots off to let my feet dry out on long hikes in. Membranes work pretty darn well.
www.salewa.com
Wiggy does have a way with words LOL!! Yes my decades of experience has led me to the same conclusion as Jerry. However, there are many others that have had the same experience as me. I happened on this video done by a woman that is an avid hiker. She shares the same experience that I've had with Gore-Tex. Her experience is very similar to the reason the Military developed the Jungle Boot. The US Soldier's fighting in hot, wet tropical climates needed footwear to keep their feet dry as possible and free of diseases that can debilitate a soldier. The Jungle Boots main design was to let water out of the boot quickly and dry as quickly as possible to keep the soldiers feet as dry as possible. If the boots had a Gore-Tex or similar lining, the soldiers would have experienced the same dilemma experienced by the woman in the video.
