Glued stair steps are coming loose

That was the OP's question - asking for proposed solutions - not about the effort... ;)

That was the OP's question - about solution suggestions - not about the effort... ;)

I wonder who designs, manufactures, and sells something like this? a design as useful as a chocolate hammer,...

Chocolate hammers probably sell well too. But not for hammering nails.

yes, you can try such solutions. But in the end, it’s fiddling around with a lot of effort just to fulfill a design.

Oh, what is effort anyway. It’s just a one-time thing and hopefully the staircase will last 20 years afterward. Therefore, I’m really open to anything.

I have now cleaned the steel and also sanded the step. It went surprisingly quickly for the wood to become light. I will now score the spot with a utility knife and then re-glue it.

I think that will fix it quickly for now, but the underlying problem remains. :/

Maybe the adhesive is also particularly poorly suited. It’s like a kind of silicone and can simply be sanded off from the steel and wood. Sure, that’s possible with any glue, but this one comes off quite quickly and easily by sanding.

I consider the idea of sockets to plug on or sleeves with threads to screw in as the most promising variant. The wood structure is not excessively stressed like with a screw, and the wood still has all the space to move. So: hole -> sleeve -> screw (in the color of the metal) from below. Form follows function!

I wonder more why you are working on it and not the carpenter who installed it? This is a new build.