The conditions where the knife is going to be used play a significant role in any answer to your query. I've found you can pretty much ruin any natural handle material if you neglect it and keep/use it in adverse conditions long enough.
Sue found out that Cocobolo, which is a pretty decent naturally stable wood, doesn't do the dishwasher environment very well.

Same with Desert Ironwood. The heat, moisture and harsh detergent do baaad things to those perfectly good woods. I didn't think it was possible to shrink and crack Desert Ironwood but she managed to do just that on the very first encounter with our dishwasher. The Cocobolo shrank and turned black as coal too. Both woods separated from the knives they were pinned and bonded to. :grumpy:
Exotic hardwood vs Kenmore will see the hardwood goin' down hard every time.
I've discovered that the Florida sun will darken both Cocobolo AND Desert Ironwood over time. Lignum Vitae is a legendary hard and tough wood that has been used for boat docks and piers here in Fla. that lasts for many decades. It oxidizes/darkens with just a few moments in the sun.
Stag needs an annual rubdown or soak in mineral oil to help keep it from shrinking, especially if it's going to see much harsh outdoor use. Now, I know there are some people out there who are going to read this and think "How does he figure that?! Those deer don't soak their freakin' antlers in mineral oil every year and I haven't yet seen a deer with shrunken antlers!" Well, those of us who've had stag handles on knives
know that stag needs to be cared for or else it tends to shrink a bit over time and with much outdoor use and exposure to adverse weather conditions. I have virtually no experience with Ram's horn so I cannot comment on that.
So, I tend to lean towards stabilized materials for anything thats going to see lots of adverse conditions and a good dose of neglect.
Things that are organic just break down over time unless given some care. If taken care of, even nominally, most
all natural handle material will last beyond our lifetimes and maybe even our children's lives.