You can't have one.
If you need to cheaply arm a bunch of clueless commie peasants who couldn't effectively clean a rifle even if they had the inclination then the AK is the way to go.
If you have infinite tax dollars provided by the American people, are a professional bureaucrat who thinks the Stoner design isn't sexy enough to get funding, then the SCAR is for you.
If you think that a national match springfield armory m1a or a socom m14 is the most accurate dependable rifle since the dawn of time despite ARs consistently beating them in all major competitions then buy all means buy one.
I'm a gun guy and given infinite amounts of money I would own multiple variations of all rifles mentioned, but since I'm on a budget I'm just going to have to stick with an AR. Sure the .223/5.56 is little better then a varmint round but guess what it can be chambered in .308 too if one had some sort of fetish for this particular round. Personally I would have to go with 6.5 Grendel.
Americans are a nation of riflemen and it's sad to see so many people jump all over weapons with sadly inferior accuracy.