It really does have an impact because the vertical is also reduced, if you compare the view
from above. 15px get 18km
and when calculating the height of the cliff he used
this point of view, it uses the same position when doing
pixel scaling here, which the viewpoint from above gets 15px = 18km, which means when using the front view angle, it has the same size, which is 18km with the number of pixels being 133px, from here we can use the pixel scaling calculation between 133px and 216px. because the actual distance of 133px is 18150 meters, we can calculate it by:
133px/18150 = 216px / X px
133X = 3920400
X = 3920400/133
X = 29476,69m
so there is nothing wrong with this calculation, because it uses consistent pixel scaling where 15px from the top POV = 133px from the front POV with a real size length of 18.15km, this is the basis for finding the height with the same point so that the pixel scaling is consistent, namely if 133px is 18150m then 216px is 29476 meters. so i think this calculation is correct, because I have checked it myself.
and the problem of buildings and others, it is not the natural geography of the genshin world but it is additional furniture, just like the characters in the game that will get a 1:1 scale