I know Paul had ranted about this before, when he left a phone behind, but you can finally remove phones that you no longer have from Phone Link/Mobile Devices in Windows: https://support.microsoft.com/en-us/windows/remove-your-mobile-device-from-phone-link-link-to-windows-and-windows-settings-e5dfe279-a38f-42c7-90bd-a82ffd70f802
Previously, these devices would only remove themselves if they “expired” and were unused for something like 6 months. Now, you can actually remove them from your list.