Basement stairs tiles connection ground floor

Hello,

At the moment, the transition between the basement stairs and the tile covering looks like this for us. In other words: In other words, the joint runs completely irregularly and becomes far too large. I want to refuse acceptance here. But what could a solution look like?
Thanks and best regards,
S.

I would also criticize that. Only a cover strip or silicone helps.

Who might be at fault? The stair builder, because the (entire) staircase was installed slightly crooked? Or are the tiles angled incorrectly? Are there two different contracting parties or just one?

Where is the problem then. Just insert a stainless steel strip (brushed) and that's that.

Who might be at fault here? The stair builder, because the (entire) staircase was installed slightly crooked? Or are the tiles skewed? Are there two different contracting parties or just one?

Staircase and tiling work are included in the house construction contract, so there is only one contact person.