Stair area 3.04m x 2.25m - 15 or 16 steps

and then you should check what else you can get up the stairs.

With a width of one meter and the clearance (I used to always think it was the stairwell, but it’s not) in the middle, you can certainly get any piece of furniture up there. But I agree with you if the landing is approximately as wide as the steps. Otherwise, it’s strange.
(the first case I know of with the desire for a landing staircase, but now it’s being shortened. I don’t want to know how many desired landing staircases become double-turned in the execution planning ;) )

Show us your planned staircase.

In a few days we have the sampling of the staircase scheduled. On the stair builder's website there are floor plan proposals for the staircase. We have planned 3.04m x 2.25m for the staircase area.

The floor height should be 2.92m, right? See also the picture.

What is there to "sample"?
In the picture I can see - as always in your builder’s phenomenally confusing drawings - nothing relevant, especially not essentials like a floor height. If you can clearly recognize in this whole nonsense what dimensions the stairwell is supposed to have, then please give me a training.

With one meter width and the free space (I always thought before that this was the stairwell opening, but it is not) in the middle, you can certainly get any furniture up there.

No stairwell opening? - then what? - the drawings, among others here: are downright exemplary unusable.

I am slowly wondering what the general contractor thinks his job is. Why does he even draw a staircase in his planning proposals instead of simply writing "staircase price included in the offer, but planning on supplier side"?

It can’t be true that a building owner is supposed to "sample" with the staircase supplier on the basis of a self-to-be-interpreted stairwell size and a similarly assumed floor height, deciding how many risers of which steepness to take. I can’t believe it. What does the general contractor do professionally, and was he found on a hot tip from Goalkeeper’s neighbor (Neo) middle-class homeowner?

Sampling of the staircase

I also have to come back to the original question: Sampling actually means that you choose the wood and the terrain as well as the flight of stairs, if the general contractor offers it.

The stair supplier suggests 16 steps for the area on the internet

As far as I know, the number of steps the staircase will ultimately have is decided with the planner, or he calculates it based on the remaining knowledge about the object. And if there is an either/or, he discusses it with you so that it is drawn into the execution planning.
But I am also happy to be corrected if it is handled differently elsewhere.

How many steps the staircase will ultimately have is, to my knowledge, coordinated with the planner, or he calculates it based on the remaining knowledge about the object. And if there is an either/or, then he speaks with you so that it is drawn into the execution planning.

That's how it is. And the rises are specified in number and dimension in the building application drawings, long before you choose the materials with the stair builder.

Show us the execution plan from the [Rohbauer]. The [Treppenbauer] will install any staircase for you. But once the concrete is poured, you can no longer decide whether 25.5 cm tread depth is sufficient for you.