I think how often you have to do this depends on your party comp. I also find the further I am into the game, the less I have to do it.
You don't have to long rest to progress the story, you can go to camp to trigger a lot of the cutscenes and for the others, you can just do a partial rest. IMO long resting is just part of this type of campaign even for RP purposes, you wouldn't be undertaking a journey of this nature without food and I think an exhaustion mechanic might have made it seem less concerning to "rest spam", but OTOH it can also be abused (e.g. long resting between boss fights).
I have a melee emphasis on my current party (Paladin, Astarion, Laezel, and Gale). I can get by with a lot less resting than I could when I went in with a mage heavy emphasis (Wizard, Wyll, Karlach, Shadowheart), which I had to do before almost every major fight. The better you understand the mechanics or the more you swap gear around to get abilities, the less you have to do it.
