I haven’t watched the challenge answer but managed to create this. It took me an hour and 30 minutes to finish. I started with a cube and made it flat and bigger (couldn’t see the grid under it). I used the insert tool and precise measurements to create 9 steps/levels, extended the tenth cube higher to create the building on top.
Then I grabbed the bottom edge of the top piece and extruded it down to the bottom of the pyramid like a ramp, extruded it out to create thickness, then pulled it away from the other piece and turned it into its own object by pressing P. created the edges by extruding the sides out, then extruded from the bottom edge up and in to create a stairway using precise x,y,z coordinates. I created 6 steps then to make the process faster I duplicated them and moved them up, then repeated (so only had to make six steps in the end).
I duplicated the stairway three more times and used the Z axis to rotate and place around the pyramid.
It was actually pretty easy to do. Now to watch how the teacher does it 