Please see: https://liftescalatorlibrary.org/paper_indexing/papers/00000...

"2.3 Non-directional collective Non-directive collective control provides a single pushbutton at each landing. This pushbutton is pressed by passengers to register a landing call irrespective of the desired direction of travel. Thus, a lift travelling upwards, for example, and detecting a landing call in its path stops to answer the call, although it may happen that the person waiting at the landing wishes to go down. This type of control is only acceptable for short travel lifts."

It doesn't; it just needs to know it was called. You make your selection once it arrives.

Look up the early history of elevators and you'll see a progression from fully manual in-car up/down controls (often with a dedicated human operator); various semi-automatic systems with minor improvements like automatic leveling and door control; and then operatorless systems that started with nondirectional calls:

https://liftescalatorlibrary.org/paper_indexing/papers/00000...

On the ground/lowest floor, there's only one button as there's only one way to go.

It is reasonable if you either have low load say a residential building where lift is often idle. Or low number of floors where travel times in either case are short.

i just saw this for the first time today in Romania...