Why? A e s t h e t i c

This has been reposted so many times. It's obviously a work in progress, with the wood from the stairs missing. The floor doesn't look finished as well.
I used to live in a home with a spiral staircase very similar in construction to the stairs in the picture. Once I removed all the wood in order to clean, fix and re-finish the wood. With the wood removed it was in fact a death trap like shown in the picture. I replaced the wood with temporary OSB cut to the right size, which actually looked kinda cool.
- with the wood from the stairs missing
  For some reason, I imagine whoever designed this would use glass.
  But agreed, it doesn't look complete.
- Pretty sure that’s finished concrete. Nothings going on top of that other than rugs and furniture.
  
  No way, it has splotches and a big unfinished ragged seam. The wall facade is also floating about an inch of the floor. This is most definitely not a finished floor.
  
  Not finished concrete at all, this floor is completely unfinished for a what looks to be a residential space.
  You would have a polish, sheen, etc. to the concrete, this just looks like what normal subfloor would look like before you put down tile, hardwood, carpet, etc.
  My basement floor looked exactly like this after we pulled up the carpet before we put down hardwood.
- I don't think is a WIP, the light fixtures are usually the last work they do to avoid broke it while doing other jobs and here there already functional.
  
  The lights are embedded in the wall and the stairs are fixed to the wall. So they probably wanted to finish out the wall before they put in the stairs. The wood of the stairs would also need to be fitted to the wall exactly, so it makes some kind of sense to finish the wall first. I would have opted for little nooks for the stairs to fit in, but there were probably reasons that didn't make sense in that situation.

This is clearly a work in progress. The stair planks are meant to bolt onto those reinforcement beams, and likely a hand rail will appear for the last half of it.
- I don't see any holes for the bolts that'd attach said planks and rail...
  Granted, the image isn't blessed with an abundance of pixels, and suffers from an excess of JPEG... but from what can be seen, I expect we'd still be able to see some trace of holes or other mounting points if this wasn't supposed to be a finished product...

WHY ARE THEY SO THIN
- WHY ARE YOU SO CHONKY.
  GOTTEM!
- To leave your prints, your evidence when you fall down.
- Isn't metal amazing? It's almost like 200lbs isn't much for a steel bar to hold up.

It does look pretty cool

My dog refuses to go up or down some types of stairs.
I get it now.
- Linoleum. He won't go down to the landing to the basement. He'll do one, maybe 2 steps. So that's where I keep his food. Even if I forget to shut the door, he won't go down there and annihilate the bag.
  
  Meanwhile, my dog is so stupid, he'll jump onto slippery vinyl floors from couches and chairs. I've actually seen him slip, fall sideways and body slam into the ground. I found him limping one time and I'm reasonably sure it was from jumping off the couch, which is when I finally put my foot down and blocked him from jumping up onto it. Built a little ramp instead.
  
  Why, if that isn't my favorite NoFx song ever. Check it out, foooooo lol

I'm a handyman. This will not pass an inspection because it lacks the handrail necessary to be code compliant. That's before even getting into tread width and lack of trip resistant rise.
- Which code though? There is no indication of where this is located. It might be perfectly fine.
- Haven't you heard? We don't do regulations in the US anymore.
  
  We did back when this meme was new, though...
  
  Codes are enforced at finalized at the local level. We've only abandoned stuff at the federal level, so far.
- Don't need an inspection if you do it yourself
  
  In most cases you'll need an inspection when you go to buy a home. Anytime you're changing a house you have to ask yourself "Will this hurt the ability to resell it later on?" This is going to end up on an inspection report and it's either going to have to be remedied or it's going to drop the value.
- Are all countries the same for housing codes?
  
  They might vary on issues like how high a riser or how wide a tread should be but if they are going to bother to have a code then they will usually contain things like the need for a railing.

I remember at my college we had stairs that had holes on the side (from the top down it covered the whole area probably with some overlap) and I used to have dreams/nightmares of having to do parkour to get through the place

Imagine being drunk

I actual quite like this. It looks totally impractical at best and dangerous at worst, but I think it looks pretty cool.

Don't run down right after hopping out of the shower
- don't take laundry or furniture up either
  
  Actually just don't try to use those stairs at all.

Definitely looks like something an architect would create...
Shame
Shame
Shame

Upstairs is where they keep all their drug money and exploits. This is a passive way to deter their parents from exploring.
- Stairs like this might deter the Boston Dynamics robo dogs the police will eventually start using in 10 years time.
  
  Well not anymore now that you bring this up. Thanks dude. Now where am I supposed to hide everything from the robot dogs?

Tell me that you don't have children (or older parents) without telling me that ..
That said I like floating stairs slightly more than these but these are good with me.
- I like that there's a "wall" as you get higher.
  
  I hear that. That's going to be a hell of a Segway!

... And slice them off on the way down.

In so much of this cookie-cutter "hip" newer housing, it's either this or a dangerously steep angle, sometimes even both at the same time.
Enshittified architects building enshittified spaces thinking only of how it looks, not how it's supposed to be lived in with safety and comfort from Day Two onward, the novelty wears off very quickly and you're stuck with an unnecessarily, potentially deadly space.
- Also it's completely not repairable. Don't get something bespoke unless you can afford it.

Add some dark wood planks or glass platters as steps and we're good.

Made from the strongest aluminum