"But what about Wizards?" you say. "I WANT to long rest between every fight so I get all my spells back."
Okay. For early game, I can understand why. You don't get a lot of spell slots to start with. However, this system still allows you to long rest as much as you want. Again, it's just that at some point you may have to spend a bit of money to do so. Small price to pay for you to get what you want. Go to a vendor, spend 300 on buying 10 camping supply packs. Leave them at camp. You now have 400 camping supplies. You get 300 from the beach to the grove. So, you have a total of 700-ish, depending on how many times you LRd on your way to the grove. Even if you LRd between every fight, you aren't full camp for most of these encounters. Intellect devourer, maybe 20 camping supplies. Fishermen, maybe 30. Gimblebock. Maybe 40. Barton and Mari and company. Maybe 50 if you picked up Lae'zel first. Otherwise, just 40 again... maybe. Scribes in the dank crypt. Maybe another 40-50. So, maybe a total of 190 camping supplies if you long rested between every fight with max companions? Still leaves you with 120 camping supplies by the time you hit the grove. Buy 400 more, and you're set for long resting your brains out in the next area. That's 300 less gp than you would have if you long rested less, but who cares. You're getting to long rest as much as you want for a very low price.
Later in the game, however, you won't even feel this as much. Level 6 wizard has 4 cantrips you can cast as much as you want, 4 level 1 spell slots, 3 level 2 and 3 level 3. Not counting cantrips, that's a total of 10 spells you can cast before needing a long rest, and if you use Arcane Recovery during a Short Rest, you could potentially gain up to 3 more level 1 spell slots for a total of 13 spells per long rest.
Jump a few more levels. Level 10 Wizard. 5 cantrips. 4 level 1, 3 level 2, 3 level 3, 3 level 4, and 2 level 5. So, a total of 15 spell slots, and with Arcane Recovery during a Short Rest, another maybe 5 more for a total of 20 spell slots.
In other words, the tougher the wizard, the less they really need to long rest between fights - provided Larian doesn't pull a bunch of "Let's make every fight super deadly so players feel they MUST LR between every fight," kind of thing.
But, even then, we have the failsafe of "You can long rest as much as you want as long as you have the money and can access a vendor."
