I have read so many security benefits to Win10 like Device Guard and Credential Guard.
Are these security features even needed for an average home user?

For example, I don't need Device Guard, because I know not to click on apps that I do not trust.
I think these are for IT admins who need to lock their systems down to prevent users not to install untrusted programs. I think...Not sure exactly.

Can you guys fill me in?

Is it this really needed for standalone Win10 machines, especially if someone knows not to install some app that is not really known?