[andrewguenther]

None. Windows Defender is actually quite good and the third party options are so bad I'd argue in many cases you're worse off having them installed.

[nix0n]

I'm assuming Windows Defender support for Windows 10 will end when Micro$oft removes support for Windows 10.

Am I wrong? Will Defender keep getting its definition updates?

Conversely, if Defender keeps getting updates, what does it even mean for Windows 10 support to end?

[TiredOfLife]

The Defender for Windows 7 still gets updates.