I've had the same Rhino hose for years...approx 7 and it still looks good. I have a backup hose, also Rhino, that I needed once due to distance from camper to sewer connection. I don't recall which one is original and which was backup. I guess it doesn't matter. My hoses rarely see the light of day, much less uv.
It's usually just the wife and I, and I only drag the hose out to dump, then rinse and connect the ends together and back in storage box. I don't leave the hose laying out. To easy for kids, dogs, or me to trip over it or step on it. Quality hoses are not cheap.
2016 Ford F-350 Lariat CC, 4x4 SRW. B&W turnover with extender. 2015 CC Silverback 29RE, fitted with Reese Goose Box. Amateur Extra Class K5TS, 2016 nights camped 16