According to the new information from Mark Gurman, Apple plans to introduce massive software updates for the Apple Watch and Mac hardware within the next few months. Among other things, watchOS 9 should significantly extend the battery life of eligible Apple Watch Series smartwatches.
https://www.notebookcheck.net/Apple-Watch-to-receive-substantial-upgrades-with-watchOS-9-macOS-13-to-benefit-from-overdue-improvements.623760.0.html