Needed? No.
I really can't see how the AR-15 fits into any reasonable standard of need.
And, really, the gun lobby goes need to think about how armed drones fit within their current philosophy. Cynically, if Winchester decides to build one, the NRA will think it's necessary and babble about how the government has them too, and it's not fair if criminals can kill people remotely, but homeowners can deploy their own armed drones into the fray like WWI-era biplanes.
Less cynically, the gun lobby will treat drones as some exoteric thing and ignore them, letting the FAA restrict armed drones. But, it's certainly coming eventually that a remote drone will be used to fly an explosive to someone—ala the "slamhound" in Gibson's "Count Zero"—or that someone will attach a pistol with a large magazine and mow down a bunch of people at a mall.
I've long said that the people who talk about the 2A as a defense against tyranny are kidding themselves, because the people who can afford guns are often part of the power structure that's tyrannical, and our current crop of "militias" are far more likely to be brown shirts, operating for a despotic government than freedom fighters.
We're seeing it even now. The militias who believe that the federal government might come to restrict our freedoms geared up and went to Portland to—checks notes—attack people who are protesting the local and federal government.
While small guerrilla forces have dented large foreign armies, even that lesson ignores the extremely high rate of civilian casualties in those wars, the value of a foreign supporter, and the chaos that comes after the fact. Essentially, the AR-15 is a symbolically a doomsday weapon.
I'll give you an extra
for the reference from the Neuromancer trilogy.
You grasped the point I was making with my drone comment. When the 2A was formulated, 'well-regulated' militias were key to maintain the independence of this nation from the Britons. Warfare shifted from gunpowder to robots since, so you need a lot more than rifles to defend from an imaginary invading force. America has a violence issue and that violence emanates into gun violence. There's a trigger on the end of violent impulses and dead bodies on the other end. This is quantifiable, reproducible and frankly, totally obvious.
This nation is fucked by lobbies from pharma hiking insulin prices, to big food selling high-fructose corn syrup or aspartame that make you diabetic, big chem that poisons your water, kills the echosystem, etc. But this isn't evil perhaps, it's greed. But when it comes to the gun lobby? They produce devices that are designed to fracture bones, rip blood vessels apart, explode brains and stop hearts. They also managed to make a deal to flood America with these devices (again more than 1 gun per each man, woman and child), and tainted every aspect of American life. Again, these issues are obvious. Gun murder rate many times higher than any other "developed" nation. Incarceration rate, many times higher than any other "developed" nation. Somehow police decimating the civilian population became a "normal" thing. It's a positive feedback loop, and all serve the purposes of those who make profit from selling guns: more weapons in the hands of bad guys=> more civilian weapons sold => more civilian weapons => bigger police weapons and the cycle continues. We also have a lot of hypocrisy here. We expect cops to de-escalate (I especially do!), but the ultimate de-escalation is reducing the number of weapons circulating. BTW, annually nearly 20K weapons get stolen or lost. To give an extreme example, how did humanity (almost...) achieve denuclearization? Definitely not by handing out more nukes to everybody.
It's all ironic, because a good proportion of people who advocate having more guns would also prefer immigration from "developed" countries, whereas for someone who is looking at America from these countries with social security, employment-independent healthcare (which is absolute key to avoid exploitation by employers), free or reasonably priced and generally higher quality education, and order of magnitude higher personal safety will perceive the USA less and less appealing. This safety gradient means, the USA will only remain appealing to those to whom this mess what we have still constitutes as safe. bRowN peOpLe!!#@&$#&!!
Additionally, it is no surprise that Dunning and Kruger described their phenomenon in the USA. We have the some most confident idiots I've ever met in my life. We even managed to elect one. How can you trust people to have the judgement to possess powers to take someone's life in an impulse, who can't even comprehend the basic necessities to keep their environments safe non-violently (yes I'm talking about COVID). So no, giving guns to everyone because it's a "right" will just hasten the downfall of this nation. And it's obvious.
/rant over