While the idea of this would be extremely cool in one sense....I just can't fathom that being a thing they develop with everything else they have to worry about.

Also, they appear to have waypoints again in BG3 for fast travel, so that's another angle that just taking that into consideration alone would dissuade any thought.

Now, if they develop actual horse mounts for cavaliers at least that can be ridden for faster (say 2x) overland travel, that might be cool....

“Any fool can criticize, condemn and complain - and most fools do. But it takes character and self control to be understanding and forgiving.”---Dale Carnegie.