In case anyone didn't catch it (most probably did), the "newer" pictures of the SKS in action are with Ukrainian irregulars in the ongoing two-way range going on over there. It's kind of fallen out of the news cycle, but it's very much an ongoing conflict.
Now, I've never been in the military, or in a gunfight (and desperately hope to never have the experience), so take my analysis with a large dose of salt. But I've been shooting off and on for close to 40 years now, and own several SKS's and a CZ-858 (as close to an AK as we can have in Canada), and an AR, M1A, etc etc., have shot them all a lot, and I can see where each type of platform has its advantages, and why the SKS is still relevant today.
The big advantage of an AK/858/AR/"modern combat rifle" over something like the SKS is ammo capacity and sustained fire. That big magazine, with all those extra bullets, are mighty handy. Especially in a co-ordinated group of people (small unit tactics). There's a lot of shooting going on in modern warfare, with not a lot of "getting shot." The statistics are pretty staggering, something like 30,000 rounds of ammo fired per casualty on average. Mostly what individuals are doing, is maintaining sustained fire to keep the other team's heads down, while the other people in your team are manoeuvring around trying to get a clean shot off that might actually hit something. In that kind of fight, you want as many rounds on tap without having to reload as possible.
The big disadvantage is bulk and weight. Yes, an AK is lighter than an SKS. But add in a full magazine, and a half dozen or 8 loaded magazines on your body, and in total, the AK ends up being pretty heavy and bulky. Sure, the barrel is shorter, but with that fat banana hanging off the bottom, the gun ends up being a lot bigger when you look at it in terms of height and weight.
The SKS fits in a different role, for a different kind of fighter. Yes, it is slightly more accurate, but I don't think that's what's really winning the day here (both will hit a bad guy size object at 300 yards or so), and why you see them in the hands of middle aged insurgents - who given the region, probably have some form of military background and training, and access to AK's is "not hard". If they really wanted one, they could probably get it.
I think where it wins out for these guys is for other reasons.
1: Simplicity. The SKS is an incredibly simple rifle. The AK may be legendary for its simplicity, but the SKS is on a whole different level of simple. Crazy easy to take down and maintain, and get it back together again.
2: No magazines. Magazines add bulk and weight. A lot more of it than you might realize. I have a couple of SKS ammo bandoleers, each can hold 200 rounds on stripper clips. This takes up a fraction of the space and weight that 7 loaded magazines would occupy (for 210 rounds). With my middle aged spread, knees and feet that have seen better days, I am 100% Ok with the concept of "every pound of crap I don't have to carry is fine by me." Being on your feet all day, and humping crap around while you do it, sucks at any age. As you get older, the challenges multiply. Trust me on this one.
3: Slimmer profile/easier to shoot prone. A standing deer is an easy shot (done it), a gopher scuttling through the grass is not. If someone is ever shooting at me, I'm going to channel my inner gopher and become one with the dirt. The magazine sticking out of a modern rifle (AK/858/AR, whatever) makes it hard to do this and still be able to shoot back. Your shoulders are going to end up being an extra 8 inches or so higher off the ground in order to be able to line up a shot. That works out to 8 inches more vertical space (and a lot more total area) for somebody else to shoot back at. With an SKS, you can lay absolutely flat, and still be able to get a cheek weld and line up a shot. That has a certain appeal.
4: Full auto only matters if you're in a group. Full auto is mostly used for suppressing fire (see above) to give your team a few moments to move. If you're alone, full auto mostly just serves to empty your magazine in a hurry. You need to make your shots count, otherwise you run out of ammo before you run out of things to fight.
For someone fighting as an insurgent, with irregular supply, indeterminate levels of supporting fire, the advantages of something like an SKS could conceivably outweigh the advantages of a more modern platform.
Anyway, for me it's all cloudbusting. Interesting to think about in the abstract. The guys who have actually had to deal with it most likely will be able to poke holes in my thoughts, and that's fine. Experience matters.