I still think it can be done, but the problem is two-fold. First, there are seemingly too many that are afraid of timed events. Second, Larian is probably afraid to try something liked timed events because it seems many people are resistant to it and they don't want to lose their fans. (Understandably so.)
But I fully believe it could be done well if people would give it a chance. I have a hard time believing that you can't simulate a DM in a lot of ways.
Here's an example of how I think it could be done in BG3:
You crash on beach. Full health. Day 1 starts. Long and Short Rests are locked. Can't do them. You meet SH and explore the area. Intellect devourer fight. DM unlocks Short Rest but Long Rest is locked unless total party spell slot count is less than 25%. It's just you and SH. Let's say combined spell slot total of 4, and you used 2. Larian as DM sets it up so that you could probably survive the next several encounters with that many spell slots and using some Hit Dice to recover HP, especially knowing Astarion and Gale are just around some corners.
Oh, but you bypass Astarion and never meet him. You also run into trouble with the fisherman. If your party has less than 25% Hit Dice and less than 50% HP OR spell slots lower than 25%, long rest unlocks. Because HP was reduced to less than 50% and no more Hit Dice, probably because you didn't add another party member, you need a long rest. The DM, the game, has analyzed that you need a long rest. You will likely not make it if you keep going.
And as far as timed events go, I've given plenty of examples. You take three long rests after learning about the ritual at the grove. Suddenly, on the fourth morning, you are met by a tiefling who tells you the ritual has been delayed. Rath interrupted it, and now he's locked up. You can either rescue him or simply leave him. It's your choice. Consequence is Rath won't help you fight Kagha unless you sneak in and break him out or prove Kagha is bad. Benefit? You get three more days to stop the ritual. After two days, someone else interrupts the ceremony, buying you more time, but now THEY are in trouble. Security in the Grove is also tighter. Tensions are mounting. Benefit? 3 more days to save the grove.
Basically, what would a DM do if players were trying to abuse resting?
A. Not allow it at certain points in the story.
B. Provide soft consequences - ones that don't ruin the main story but might make things a bit more challenging to the players; events that make sense from a story perspective.
They actually did do some of this originally, but I didn't realize it until too late. If you rested immediately, origin characters would heckle you. "Why are we resting? We have tadpoles in our heads."
The problem was, Larian didn't follow through with this. Soft reminders you are resting too much could be dreams with the dream lover. It could be people threatening to leave the party or threatening to take matters into their own hands. I mean, there are SO many ways to do it besides hard limits.
You haven't fully thought through one thing, and that is the number of possible permutations.
The game already provides a huge number of possible options or reactions to the player's actions, and the events you are talking about would require much more.
I don't know if it would just be too much for them to finish this game in a reasonable time, and the budget is hardly made of rubber.
More complexity also means more potential bugs, so that it does not end in a disaster on the WotR level (at the premiere it was barely possible to complete it or not).
One more thing is that the big changes in act 1 will make the later acts much worse (like in every game Larian made).
As for the other limitation, it is exactly as mentioned by Ragnarok.
Ultimately, the effect is completely opposite to what was expected.
If you can't rest when you have too many slots for spells, why not use them all in one fight or burn them all when you want to rest.
Limiting HP is also not a problem, lowering your hp to an appropriate level is not a problem at all.
Theoretically, the solution was the CD, but here we enter the area where the game is potentially irritating.
