It boils down to limiting Long Rests more. If you weren't able to simply spam Long Rests, you'd use more of your spell scrolls and potions and magic arrows and such. That's actually one of the main reasons I keep saying that there needs to be more restrictions on Long Rests. If you restrict Long Rest more, scrolls and potions become SO much more important, as do magic items in general.
Think about it. If you are a Wizard with a total of 6 spell slots per long rest. You pick up 8 scrolls and 6 potions of various kinds. You fight through your first battle of the day against (let's just say) the goblins in Bogrot. Dang! You used 4 spell slots. You fight the next group of goblins. Dang! You used up the rest of your spell slots. Short rest. You use Arcane Recovery. Ah. You have more spell slots. You fight the ogres. Dang! Out of spell slots now and you even used 1 of your 8 scrolls to be able to continue casting spells. You still have 7 scrolls left. Game still won't let you long rest. Guess you have to rely on those 7 scrolls to continue to cast spells. You use 4 scrolls in the next fight against the undead outside the Necromancer's Lair. Darn! Only 3 more to go. You complete the Necromancer's Lair area. Bing! Long Rest available. Thank God! Now I still have 3 scrolls and I can recover all my HP and spell slots. Maybe I should go back to the merchant and buy a few more scrolls for tomorrow.
That's how D&D is supposed to work when it comes to spellcasters. The scrolls are supposed to supplement the restrictions you have in terms of spell slots. That's the entire purpose of having scrolls. If you can Long Rest between every fight, you don't need scrolls anymore. Just sell them. The same is true for healing potions. If you can long rest between every fight without restraint, you can literally use your cleric's or druid's healing spells every fight until you are out of spell slots and then return to camp and rest. No potions necessary to supplement or offset the fact that you can't just long rest all the time.
But that said, I REALLY don't like the idea of spoiling potions, scrolls, etc. They are meant to be relied upon so that you CAN save them for when you need them. The last thing I want is to have a stockpile of 20 healing potions and when I need them in my battle against a dragon or mind flayer, I discover that 18 of them lost their magical potency and are useless. Now, when I need them, I"m doomed all because they spoiled. Yeah. No thanks. I'd much rather have Larian provide me with harsher direct restrictions to long rests than have them spoil items like potions and jazz, and frankly it still doesn't limit long rests. All it does is makes me want to sell such items right away so that I can get full gold value from them. Then I'll still use my spells to heal and rest frequently.
