Covering for indoor concrete stairs -> wood, vinyl, natural stone?

The choice of material and folding structure or not depends on the intended dimensions for the support. The reference to the geometry has already been mentioned several times. Wood folding structure is great - but looks shabby on a staircase not made for it, results in a higher step at the bottom, and has no proper finish at the top. Wood is certainly a good choice, but if it does not fit the design of the staircase, it is simply nonsense.

Since nothing was found in the construction description, I asked. According to the developer, a 1cm wood flooring was planned. Can that even be possible? What kind of quality would that be? Or does that not mean anything?

According to the developer, a 1cm wooden covering was planned.

Really strange size. Would fit for tiles/porcelain stoneware.

What is Faltwerk on a concrete staircase?
Isn't a Faltwerktreppe defined by a massive wooden construction without substructure?

Please take a photo of the staircase and how it looks from the living areas.

What is folding work on a concrete staircase?

This:

Thank you. I didn't know that they are also called [Faltwerktreppe] when they have a substructure. Learned something new.