AR15's: Can someone explain to me why they're so popular?

As I see it, the 308/6.5/6mm are superior for long range engagements and anything under 100m can have pistol calibers perform the same function as a 223/5.56 (with the bonus of it being quieter).<br><br>I understand if you're in the military and you're concerned about weight, but what are the advantages of owning an AR15 for those who aren't (and don't plan on) serving? Are they just popular because they're something that can be used with magazines in a home defense situation? <br><br>I understand that it's the right to bear arms, but if I'm going to invest in a gun, I'd rather it have some practical uses. (Sometimes I wish I could just ask a questions without sounding so anti gun smh)<br><br>EDIT: Sorry guys, I'm broke rn and my wifi isn't working so I can't reply to any comments. Love y'all though, but I think I'll hold off on the AR15's for now.