Leveling stairs with screed or WEDI - what do you recommend?

Hello everyone,

we have a concrete staircase that is simply poorly concreted. The tread does not fit and the steps themselves are not optimal at the beginning or end with today's floor construction.
How would you level the staircase? Formwork and pour screed or, for example, use Wedi panels?
One tiler recommended WEDI, another said formwork and pour screed.
I find the WEDI option more appealing. What is your opinion/experience?

Wedi is faster but always sounds as if the tiles are hollow, how many cm are we talking about per step?

Construction above would be 6cm.... But the tread also has to be deeper, I think that must then be built up on the front side between 2..3 CM. Do you think that fits for wedi?

The tread must be 6cm higher for all steps ? and riser (in your case front side) + 2-3 cm?? Then stick 5 mm Wedi on the tread and fill the riser, what kind of covering should actually go on it?

Filling? With which material? Tile adhesive? 2..3cm? Tiles are supposed to go on it. Thanks in advance!

There is a fast filler from Ardex. Ardex A 46