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

By the way, well-oiled wood forgives, can also handle small stones and scratches better than you think. But it is more expensive. I would only worry about moisture with wood. Are tiles not an option? They are probably quite high on the easy-care and durable scale and not necessarily that high on the price scale (although every flooring is basically open-ended on the upper limit). However, I have seen tiles for 7 EUR/m², not vinyl or parquet.

The question is also whether it should be merely functional or stylish. Basically, in my opinion, the same type of wood as your floor would be appropriate. Natural stone or similar is also slippery, especially when wet, and moreover cold. If you don't deal with water by the bucketful, a little water does nothing to the wood. With oiled or waxed wood, small damages can be easily repaired. With tiles, for example, that is difficult. I wouldn't choose vinyl or similar; I would prefer a solid building material, also because of the side view.

Thank you for your answers. Usually, the first idea is the best. Theoretically, parquet would probably also be an option. It is definitely also about the appearance, since the staircase will be visible from the living area. If I decide on wood, there remains the question of whether [Faltwerk] or just applied steps. [Faltwerk] makes it very expensive, I fear...

That is a matter of taste, of course, although I find a stylish applied step with robust material nice. At the same price, I could also consider folding construction, but I don't really like it better nor would I want to pay significantly more for it. I'd rather invest that elsewhere. You could color the concrete side or design it in another way for contrast. I'm not a stair expert, but from the side view, with parquet and other coverings, you have an unattractive view and somehow have to cover it up with moldings or similar stuff. With solid wood, it's different and thus simpler and more elegant. I'm also already considering this and that for our stairs soon, but it will probably be this classic variant as well. Maybe choose a specific type of wood or a colored stain.

So, folded structure can look very good; in particular, white risers, for example, are quite maintenance-intensive. Especially if the house is otherwise rather modern and simple, I would definitely go for the folded structure. And a staircase made of oak wood is already sturdy!

We had our concrete staircase completely covered with wood - oak - folding structure 45mm.
It really looks amazing... but it comes with an amazing price

... would do it the same way again though