Microsoft explains why it killed Windows phone activation

In December, Microsoft unexpectedly removed the last remaining method for activating Windows without an internet connection.
ZDNet

Need to activate Windows? Microsoft just eliminated an option I've relied on for years

Phone activation for Windows has been discontinued. You'll have to use an online portal to activate Windows. The portal requires a Microsoft or business account. Microsoft has typically offered a few ...
Windows Report

Here’s Why Microsoft Ditched Phone-Based Windows Activation for an Internet-First System

Microsoft explains why it removed phone-based Windows activation, shifting to an online portal for a more secure and reliable ...