Why is this not implemented?

See those curves on the right, they are never made as 1 piece slope rails. The sense of direction of the curves. Why? This is actually very dangerous if the rails are at a tall height, the 1 piece curves have a small slope gradient on the grooves, this mitigates stability issues. If you were to use the 2 piece structure continuously to make a tower, you will find that the tower is unstable due to lack of gradient. Is there any logical reason not to produce these 2 piece structures as a 1 piece sloped curve rail?

Backstory, the sloped curve rail has 3 variants. 1: Darker blue, very hard plastic. 2: Lighter blue, very hard plastic. 3: Lighter blue, soft plastic.
1 and 2 are the oldest rails and 3 is introduced in late 2019. The late 2019 has also made 3 kinds of block piers, namely S, M and L, for the slope curve rails to rest on. However people are saying that this is a waste of time of production and older block piers (in the picture) are still used.