Rolex watches are known to be very reliable. If this is true, what makes Rolex movements more reliable and dependable than other movements such as ETA 2824/2892? I have read about how Rolexes and some Seiko movements can sometimes go without service for 15-20 years. However, it seems that this is not the case with ETA movements (at least from multiple forum threads on the subject).
Reading articles on both ETA movements and Rolex caliber 3135, the Rolex movements do not use ball bearings for its rotor which is considered a weakness to its longevity -- one of the first things to go so to speak. What is the weakness or weaknesses of the ETA 2824/2892 that cause them to break down prior to the Rolex calibre if neither are serviced?