WolfsForge

"barrel was moving at least 1-2 milometers from side-to-side in between every shot"
If the barrel is not securely fastened to the receiver, the weapon is faulty and must be repaired before an accident occurs.

3.55
If you mean the barrel vibrations that inevitably occur during a shot, this is normal. Designers develop weapons taking these vibrations into account, and each subsequent shot occurs after the barrel has returned to a straight axis line.

Neither the AK-47 / AKM nor the AK74 / AK-74M are designed to hit targets at a distance of 500 m. This is the operating range of other weapons.

I watch his videos sometimes. Very often, Soviet-Russian weapons appear in versions of other countries that have received a license for production. I don't know whether this is good or bad)

Как именно называть зависит больше от тусовки, в которой человек обитает.
Можно называть АК, можно называть АК-47, это равнозначно. Хотя я и встречал граждан, которые "нееееет, нельзя называть АК как АК-47, такого автомата не существует!". Зачем так упираться в таком пустячном вопросе мне не понятно

Who are we?

In American circles, the AK-74 is generally well regarded, while the AK-47 isn't. Part of this comes from the main source of introduction to the rifle, which was the exported models.
That's a very good point, thank you.

Though it's usually praised for reliability in dirty conditions, those loose tolerances cause a loss to accuracy over distance.
This is quite an interesting question. I can't say anything about export models for obvious reasons.

However, if you look at the design of any AK-based assault rifle and any AR-based assault rifle, the AK will indeed have much more voids and larger tolerances between parts. This is certainly not done so that low-skilled workers could make parts with large tolerances and it would work (I've heard this version). The point is that automation that allows operation with such large tolerances will be more reliable, since large deviations from the norm are allowed. We are talking about heating, cooling, contamination and moisture.

There is no relationship between these tolerances and accuracy. But since we are talking about accuracy, it is worth citing data from Technical report No-46:

It is a bit overkill and causes some issues, true, but it was meant to solve that issue.
The problem is that the AK provides reliable operation of the weapon without a well (well?). At the same time, a better connection with the receiver, since the protrusion on the magazine is supported by a spring-loaded latch on the other side. In AR systems, the magazine is held by only one latch.

I can't speak for the entire model range, but in one of the YouTube videos, a shooter who prefers the AR platform talked about the problem when loading more than 28 rounds into the magazine - it begins to fit tightly into the well. And we are talking about greenhouse conditions.

And how much dirt can such a well scoop up in a real war

There are folding stocks for the AR platform, though I don't know if the US military uses any, since they prefer the retractable ones.

You are absolutely right, the US Army does use retractable stocks. However, this is more about adjusting the length of the stock to the user and his equipment. That is a different case. The same adjustment, coupled with folding, is present in the unsuccessful AK-12:

But there are also fully folding stocks for AR:

True, in this case you have to fold the butt together with the tube. Apparently, folding the butt in this case will take more time, and using the weapon with the butt folded is completely impossible.
The stock can be folded in AR-based weapons that use a short-stroke piston system, but such systems have their own serious problems.

I know that guys in the US military don't report any troubles with the retractable stocks in CQC (I know quite a few.) I also know that the US views "trench-warfare" as a wasteful tactic, since it greatly increases chances for losses, preferring to punch through any defenses with a mixed armor/air/artillery strike.
It seems unlikely that soldiers would engage in hand-to-hand combat today. Knives are used to covertly eliminate sentries and enemy personnel, while the use of an assault rifle in close combat is unlikely.

During World War II, Germany showed the world the potential of maneuver warfare with tank breakthroughs. I do not exclude, as some like to do in the drone euphoria, the possibility of breakthroughs using aircraft, tanks or - theoretically - nuclear weapons.

However, if this happens, then there will still be combat-ready infantry in the trenches. If this does not happen, then it will be even more necessary to storm the trenches. And in a trench, the shorter the weapon, the better, and it is not the one who shoots more accurately who survives, but the one who quickly detects the enemy and starts shooting in his direction. Then the automatic weapons will do their job.
Some assault troops even use the AKS-74U with 45-round RPK-74 magazines