It's missing because there are only so many developers at the Foundation and so many hours in the day and nobody has made the case that this feature should have priority over the others in the long list of features they would like to implement. They don't copy back from the fork for the same reason: no people available to do it and all the other things they want.
This is not unique to Blender. Every successful software project has a long list of desired features and far too few people to implement them all; so somebody has to decide what order to implement things in.
There is a forum, Right-Click Select, for suggesting features, and you can track various ToDo lists, like this one for the User Interface at the Blender Foundation that show what features they would like to add. They're also pretty open about what they're working on and have planned.
Bforartists is an excellent fork but the developers who maintain it have different priorities than the developers who work at the foundation. That's why they forked it in the first place. They do stay very current with the main tree, and if you like their approach to user interfaces, I strongly suggest using the fork.