Obvious way to differentiate?
Not long ago, nearly all cars more than a few years old were rusting away. Manufacturers thought that the buyers of new cars disposed of them after at most two years, so their customers wouldn't worry about obsolescence. Then Japanese makers introduced long non-rust guarantees and ran away with the market, until the rest followed.
Now almost all phones more than a few years old are a significant security risk. Who will be first to sell phones with guaranteed updates for five years, at a competitive price?