Yes, they can tell the time but there are better ways of knowing the time nowadays. Especially if you care about accuracy, a smartwatch connected to a smartphone connected to an atomic clock is more accurate than your Rolex.
So what's the point of jewelry? Fashion, and signaling your wealth mostly.
I agree that expensive watches are mostly status symbols, but a quartz watch is accurate to about 15 seconds a month, which unless you're in the military is good enough accuracy, may I ask what you do day-to-day that requires you to have atomic-clock levels of time accuracy?