Visionaire uses the way paths to determine the closest one & which path to take from wherever the playable character is standing whenever the player clicks outside of the way system borders. Paths are also used to navigate around cutouts inside of the way border; regardless of whether the player clicked inside of or outside of the way border.
Typically what happens when the player clicks inside of the way border, the engine will automatically calculate the most direct route from the current position to the destination position, which in most cases is a straight line; unless that's not possible because the way system border has a really complex shape or there's a cutout in the way.
By the way, if you want to see what the way system & engine is doing (to a degree), press TAB while running your project via the editor & turn on "display waysystem" in the overview tab.
As for Daedalic & their games... to my knowledge they used interns & inexeperienced people to do a lot of the grunt work, & setting up the way system to behave exactly how you want it to behave is no easy task.
In regard to your last remark, I'm not going to blame the customer, but to me it sounds like you just want create a game without putting in the work. Unfortunately for you, game development involves a lot of tedious/repetitive work; regardless of which game genre you are working on & which game engine you decide to use.