Windows 10’s Timeline feature is going away - The Verge

Timeline, first launched in 2017, was designed to make it easier for users to swap between multiple devices — transitioning seamlessly from a Windows 10 PC to an Android or iOS phone and back again.

It’s no surprise that Timeline is getting deprecated: it was a feature that heavily relied on Microsoft’s Cortana assistant, which would prompt users to resume tasks from device to device.

Cortana was a particularly important part of building out the Timeline experience on iOS and Android devices, where Microsoft (obviously) had less control.