You probably should be getting the automatic serviced every 10 years. That basically involves cleaning it, replacing the mainspring, and applying new lubricant. If it's a dive watch, they would also replace the gaskets which dry out.
The last time I persuaded him to give it for service he complained that the service cost was 3x what he had paid for the watch in the first place. For months.
He had fashioned a strap for the watch using a piece of rubber when the bracelet broke and was perfectly happy with that unsightly arrangement.
Well, that at least establishes how much he values the watch.
Luckily for him, the market for watches is big and when he finally needs something new he has a lot to choose from. The watches on the low end are better than ever and the watches on the high end are excellent but crazy expensive.
Sistem 51.
Once you're out of warranty you're done.
Meanwhile my dad's 40 year old Swiss automatic has been serviced just 2 times, and the last time was 10 years ago when the integrated bracelet broke.