Does graphene last longer than ceramic?
Quick answer: Often, yes. A graphene coating built on an SiO2 base tends to be a little more flexible and more resistant to heat and oxidation than a straight ceramic coating, so durability can edge out. It is not guaranteed -- formulation, preparation and aftercare still do most of the work, and a good ceramic already lasts years.
Graphene is usually marketed as the longer-lasting option, and there is truth in that, but it needs context. Both graphene and ceramic coatings bond at a molecular level to the clear coat and cure to an ultra-thin, hard layer that shrugs off chemicals, UV and contamination. The difference is in the chemistry, not the principle. Traditional ceramics use silicon dioxide (SiO2); graphene coatings keep that SiO2 backbone and add graphene oxide or derivatives. The graphene can make the film a touch more flexible, more resistant to micro-cracking, and better behaved under heat -- which should translate to a longer life in harsh real-world conditions.
Does that mean graphene beats every ceramic? No. Longevity is driven just as much by the specific product, prep on the day, and how the car is looked after afterwards. A good ceramic, applied properly and kept clean, runs for years; a graphene hybrid should push that further. Graphene hasn't been around long enough for a definitive verdict, but from what we've seen so far it does appear tougher against everyday abuse -- and we'd put our money on it lasting a bit longer.
What actually decides how long either lasts: outside storage, high mileage, winter salt, strong traffic film removers, brush washes, poor wash technique and hard-water spotting all shorten lifespan. A garaged car with sensible maintenance gets far more out of either coating than a neglected one with the "better" chemistry.
For the broader question of whether graphene's extra cost is worth it for your car (covering chemistry, scratch resistance and value alongside durability), see is graphene worth the extra cost over ceramic?. For the lifespan question on ceramics specifically, see how long will a ceramic coating last?