Need to back and check my watch. In the drawer for years

It is not mechanical. I have to go to Menara Goodhill for battery replacement The battery last probably no less than 4 years I guess.

Mechanical watch time will drift over time because machining mechanical part has imperfection due to machine tolerance.

Traditional battery watches runs on internal quartz or crystal oscillator which is very accurate but over long period will also drift. The microseconds inaccuracy is diving clock pulse will accumulate over time. Battery factor will only comes to very end of battery life cycle because the circuitry can be designed to drive at constant current.

If accuracy is very important, then you need to go for watches that sync with cellular base station or GPS. Your phone use clock data from cell station which is synchronized to GPS satellite. Yes, due to distance from satellite to earth, the info delay 1s+ (no more than 2s if not mistaken), but the GPS receiver has auto-compensation to calibrate itself.

It is no more about time accuracy when person wear those watches