HKLM\SOFTWARE\WOW6432Node\Microsoft\Windows\CurrentVersion\Uninstall\Microsoft Edge, remove NoRemove.
HKLM\SOFTWARE\WOW6432Node\Microsoft\EdgeUpdate\ClientState\{56EB18F8-B008-4CBD-B6D2-8C97FE7E9062}, delete experiment_control_labels if it exists.
Create HKLM\SOFTWARE\WOW6432Node\Microsoft\EdgeUpdateDev and add the AllowUninstall value. This replaces the experiment_control_labels blocker on later versions of Edge Update.
Run uninstall in Settings or Control Panel.
If both WebView2 and Edge Chromium are uninstalled, Microsoft Edge Update will uninstall itself.
Delete HKLM\SOFTWARE\Microsoft\Windows\CurrentVersion\Appx\AppxAllUserStore\InboxApplications\Microsoft.MicrosoftEdge_x.x.x.x_neutral__8wekyb3d8bbwe (The version will vary depending on your Windows version). This will ensure EdgeUWP is not installed on new accounts.
To remove EdgeUWP on existing accounts, create a key under EndOfLife named the SID of the account that has EdgeUWP, and create a key under that named Microsoft.MicrosoftEdge_8wekyb3d8bbwe. After that, you can use Remove-AppxPackage in powershell to remove. Remove the Microsoft.MicrosoftEdge_8wekyb3d8bbwe key after (THIS STEP IS IMPORTANT, WINDOWS UPDATE WILL ERROR IF YOU DON'T!).
A repair install or upgrade will restore both Edge Chromium and EdgeUWP. Edge Chromium can also be reinstalled using the installer. (https://www.microsoft.com/en-us/edge/download)