Palm Jumeirah villa, the sea-facing walls blister and fade way faster than the rest, what exterior paint actually lasts here?

You have already spotted the key thing yourself, on the Palm it is the sea-facing elevations that take the punishment, direct salt, spray and UV, while the sheltered walls barely age, so the answer is to spec for that exposure rather than repaint everything on the same cycle. What lasts on the exposed walls is a proper exterior, UV-stable and often elastomeric paint system applied over correct prep, meaning the old chalking, blistered coating is properly removed back to a sound surface, any salt is washed off, and the wall is primed before topcoat; skip that prep and even a good paint lets go early because it is bonding to a contaminated, powdery surface. Two habits then stretch it a long way: a periodic freshwater rinse of the seafront elevations to get the salt off, and catching a blister or a chalky patch early with a local touch-up instead of waiting for the whole wall to fail. So it is the right system plus real prep plus a light rhythm, focused on the exposed side. A finishing team that knows Palm Jumeirah and seafront villas will spec the exposed elevations differently to the sheltered ones and get the prep right, which is where the longevity actually comes from. Redoing it in a standard paint over a quick sand is exactly what restarts the two-year cycle.