Mirrorrorrim
Hero
Spells are already power modules that can be reskinned however one wants. Many spellcasting classes need to be able to do the same things to be able to fulfill roles within a party. Damage, Healing, Buffs, Control, etc. Making sure every class has their own unique spells that cover the same party needs/roles sounds like book bloat to me. There just isn't enough room in a physical book to make sure every class has unique spells that do effectively the same thing as other spells of other classes. That would double the size of the spell chapter. Creating variations of damaging spells is less problematic other than bloat, but does every spellcasting class that heals have to have a couple 1st level healing spells that are different than the healing spells of other classes? Lesser Restoration? Counterspell? Remove Curse? How many different spells need to be created for the illusion of difference?
And you can't say that only Clerics can heal, only Bards can charm, only Wizards can blast AoE fire, or only Warlocks can bestow curses. That negates so many character ideas.
And who wants their favorite class to have a very small, curated spell list that makes them even more cookie cutter compared to other members of that class? What is better? Every bard having the same limited spell list and looks like every other bard? Or large cross-class spell lists so the player can craft the type of bard they want, even if there is some overlap of spell collection with a cleric or wizard?
And when it comes to publishers creating more spells, if there is no or little overlap between spell lists, all those cool ideas are worthless if no one is playing that specific class.
In a video game like WoW or a smaller RPG with a narrow, less expansive scope, a smaller, curated list can be good at making classes feel different from each other, but make members of the same class look more homogenized. D&D is published as an expansive sandbox that gives access to large toolboxes so players can craft the characters they want.
All that said, I'm fine with each class having some spells that no other classes get, like Eldritch Blast, or Animal Shapes. Heck, as a house rule, I might allow each Subclass to have unique spells. Like Spellfire Storm for the Spellfire Sorcerer. It could make narrative sense to some that only Spellfire Sorcerers get access to it. But if you look at it from a character design and publishing perspective, how useful is it to be published in a book if no one gets to use that spell unless they have selected that Subclass? What if the subclass is otherwise uninteresting? That spell is worthless and a waste of space in a book. But if a player wanted to play a Spellfire Sorcerer with Spellfire spells, I could see myself house-ruling that his Bladesinger Wizard buddy couldn't select those same spells, just to protect the identity and uniqueness of that Sorcerer. The Wizard already has a much larger spell list that the Sorcerer doesn't get, but I'd also consider saying that only the Bladesinger could select certain sword-themed spells in a specific campaign.
Essentially I could see limiting options at a specific table as a house rule, but not in the published books.
You only get sneak attack once per turn. Getting an extra attack with advantage as a bonus action doesn't change that.
