If thats the case, thats insane. The plain old rubber brake lines - not to mention fancy braided ones - in your car last more or less last the life of the vehicle, have an operating range in the order of 500 - 1500 PSI and can cop cop well over 200 deg c. The maximum domestic water pressure is a paltry 72 psi and perhaps a max temp of 75 deg (unless you fiddle with the thermostat) plus the hoses under a sink operate in a far less hostile environment. In fairness, I'm not comparing apples to apples here, but obviously the materials and construction method for any fitting you need to swap out every five years are total ****. A tap washer is about the only thing in a domestic water system that should require freshening up now and then.
Abey, last time I looked, gave a ten year warranty on their flexible fittings.