I think instead of restricting rest, they should design more time sensitive encounters. Like with the burning building for example, if you go there, see it's on fire, and decide to take a long rest without helping, then those "8 hours" should change your ability to rescue certain characters.
This leaves players with choice, but also makes the decision matter. Sometimes you might want to push your characters because you have a problem in front of you that will get worse if you give it time, but sometimes you might not care/it might not be worth it to engage in the danger without recovering.
