In addition to removing Bing engine, remember that you can totally remove all Modern Apps you do not like and use with PowerShell. As you know simply uninstalling a Modern App quite often does nothing else but simply removes the app from Start, leaving it on hard disk ready to be "re-installed", added to Start again.
Just uninstall the apps you do not need, then open the PowerShell or PowerShell ISE and give this command:
The command explained:
Get-AppxPackage | Out-GridView -PassThru | Remove-AppxPackage
Get-Appxpackage (AppxPackage = App) lists all Modern Apps on your hard disk, the pipe ('|') symbol then "pipes" (sends) the output to cmdlet Out-GridView to be presented in table which passes the user selection through (switch -PassThru), piping it to cmdlet Remove-Appxpackage:
Select your uninstalled apps you'd like to remove completely if they are still shown after you uninstalled them, click OK and you are done (in above example screenshot I removed an app from a Finnish newspaper which does not work, and Bing Health).
You can now check that they are really gone by giving the "list all apps" cmdlet piping it to grid tabel with this command:
Get-AppxPackage | Out-GridView