Did it not occur to you for a second that maybe actual rest system is simply not in yet?
Mind blowing revelation, I know.
Well, I guess we'll know when Larian will starts talking about it.
They are busy making the game, not explaining obvious shit to people every step.
Rest, as it's now, quite obviously won't stay for actual launch. It exists in current form so we could actually play, but it's pretty clear it's a major WIP there with them deciding/working on exact limitations and triggers. There are already spots in EA as is where long rest does not work and you need to go to safe area to actually do it - Hag's den for one, pretty clearly they are considering at the very least area-based restrictions, but I bet there will be more to that too, whether it's some sort of limited resource for resting or some other solution they will come up with.
The thing is, it's simply not done yet, clearly. Mommy and Daddy Larian does not need to come out and state the obvious.