Google Chrome engineers are working on a throttling system that would impose a limitation on the number of JavaScript (timers) operations that unfocused background tabs can perform. This would reduce the CPU usage coming from Chrome’s background tabs, indirectly improving the browser’s performance and the device’s battery life. Google plans to ship this feature for all six Blink platforms: Windows, Mac, Linux, Chrome OS, Android, and Android WebView. Developers have voiced concern that this mechanism might ruin real-time applications such as Slack, Discord, and others, who rely on timers to power many of their features.
Source: https://www.bleepingcomputer.com/news/software/chrome-plans-to-limit-the-activity-of-background-tabs-to-improve-performance/