I have a early Seiko Quartz 0624 LCD from 1974 that still functions perfectly along with an early Zenith Defy Quartz from 1975 that also keeps great time. If you maintain older Quartz watches and make sure to regularly change the battery so the internals don’t get ruined they literally pretty much last forever. The massive exception to the rule being LED watches as eventually the LED anode will deteriorate with regular use, especially with older LEDs.