Why does Windows upload location (GPS data) to the Microsoft Account servers?

When you start a new Windows PC, it asks if it can use your location. See screenshot below.

According to the terms, Windows wants to use the built-in GPS on my laptop, and upload my location to Microsoft Account.

Why?

What feature can you possibly use, which reads your location from your online Microsoft Account, instead of directly from your device?

Surprisingly, your location will be uploaded even if you do not turn on “Find my device”. It only needs you to turn on “use my location”, aka “Location services”.

Note: even on devices without GPS, you can often have good location data. The BSSID / MAC address of your Wi-Fi network has typically been geo-located by a commercial service. This may be from your phone, a neighbours phone, or a Google Streetview car, etc.

Context

Windows requires creating a Microsoft Account (as of 2024/5).

If (and only if) you tap “Learn more” on the location settings screen, you realize:

If an app or feature accesses the device’s location and you are signed in with your Microsoft account, your last-known location information is also saved to the cloud. This information is available across your devices to other apps or services that use your Microsoft account and to which you’ve granted permission.

• Windows location service and privacy

Features which access location include the weather, as mentioned during setup. The weather is automatically shown on the taskbar, lock screen, etc. Location is also used if you turn on ‘Night Light’.

In other words, the location will be uploaded immediately, and Windows will keep doing this. Unless you turn the location setting off. Or unless you turn off Weather everywhere, do not use ‘Night Light’, etc.

Screenshot