To be honest, I have nothing to add to what has already been said. However, I want to tell you this:
I am an experienced, you might even say advanced Windows and PC user. With that I mean that I know which email attachments to open and which not, which links to click and which not, which sites to go and which not. I do no torrenting, download no pirated software, do not visit (too often
) adult websites.
Since the day I started to use first preview versions of Windows 10, October 1st 2014, my only protection has been Windows Defender and Windows Firewall. Not once have I used any other third party AV or firewall applications. For instance, I have never used Malwarebytes.
I've had 0 infections, I've had 0 malware issues.
Short: Yes, Windows 10 built-in, native Windows Defender together with Windows Firewall is all you need.
Kari