Larian has said they'll probably add some sort of solo mode in for release, and you can use that.
Nobody is going to eat your steak. Hundreds of thousands of people will be playing this game. It might surprise you to learn that no, you are not in fact entitled to have the default game balance which everyone will use designed so that a solo player in this game (which has mechanics based around a 4-person party) can breeze through the game on Normal difficulty. The customer is not always right, even if you paid $60 USD - especially when there are so many customers with conflicting desires.
I don’t rest after every battle, and I don’t expect the devs to cater to a select few or design the game so that it can be run solo.
I’ve run every class solo through act 1 just for kicks cause the game is boring at this point (until more content is released). Cleric is the last class I’m running and I just finished the blighted village without resting (to include the 3 ogres) and I’m going to rest now that I’m done with it before I move on to the goblin camp.
You absolutely do not have to rest after each battle, but if anyone chooses to do that, they should completely have that option.
Everyone is so hell bent on this being 5E, when it’s never going to completely follow 5E rules. That would require an insurmountable amount of coding and the game would never get released.
In the end, the game will be what it will be, and all players, happy or unhappy, will have to take it as it is. If they put restrictions on resting, I personally don’t care, but I wouldn’t expect anything like that anytime soon. There’s numerous bugs and other issues that need to be fixed before they implement a major coding patch for resting. Personally, I would prefer they focus on new content opposed to addressing something petty like people “abusing” resting and enjoying their game.