Renovate free-swinging concrete stonework stairs

I would leave the steps as they are and tackle the railing and the wall color.

I think the staircase and railing have something and go well together. I would leave it. Dark wall color as contrast I find good and above all the adjacent floors need to be new for a modern look. Then the staircase really comes into its own.

What do you think of microcement? Beton Ciré, etc. It really looks great on the internet. The question is whether it is elastic enough. Apparently, it adheres well to tiles, so it should also hold on these steps.

The steps made of concrete stone hardly bend. A coating tolerates that slightly. Preparation is important. Sanding, removing old sealants. As I understand it, Beton Cire is more suitable for horizontal surfaces. When choosing the coating, pay attention to the desired surface roughness and abrasion resistance. Just ask the painter you trust how he would professionally coat the steps. As mentioned, painting the walls is probably nicer and cheaper.