My ski jackets which are goretex easily last 10+ years. Membranes are things that usually fail. I had a raincoat membrane fail while I was in Thailand during the monsoon season. It was a cheap rain coat at a 1/3 the price of a goretex equivalent. REI wouldn’t take back the raincoat even though it was only 4 years old so I replaced it with goretex active coat which is still going strong though I burned a couple holes in it that I had to plug with wax. I don’t think it’s unreasonable for a waterproof membrane to last the life of garment. Most of my camping gear is 20 years old and still works fine.