The technology in a Rolex is stable, it works and does what it is designed to do well. It also has the joy of not becoming outdated in 6 months time.
In 25 years time, with a bit of a refresh, like a new battery or a wind, the Rolex will carry on working as it was designed to do on day 1. You won't need to dig out an old iPhone and find the correct OS version to just boot it up. That is of course if you still have a compatible charging cable.