Weapons aren't really analogous with Spells, though. Weapons are concrete items you can use over and over again, and share with someone else, which anyone can use. While Spells are bits of magical energy that go away the moment they're used up, and are unique to the caster.
We're talking about mechanics that dictate how Casters "do things". Pragmatically, a warrior is just a guy that can attack/shoot a weapon. A caster is someone that can blast spells.
In game - this is why emergent qualities have come up in modern DnD play as Damage Per Round, and Builds, the 15-minute casting day. And GM design goes by Encounters Per Day.
Mind you - we're not talking about narrative roleplaying theories on what a Fighter does when he's not fighting - that comes into play too. We're talking about the practical realities of what PC's do in game. That means 90% of it combat.
So sure I can swing my sword at 5th level once per round. Maybe twice? And hit you for 1d8+Str. in damage. Meanwhile the Wizard can shoot his fireball a couple of times (maybe squeeze more depending on the edition) for 5d6 area effect. The reality is when the monsters are dead, the combat is over. The key thing we're talking about here are the mechanics used to engage in the classes actions are not simpatico in expression OR effect. That a warrior can swing a sword over and over says nothing about HOW he swings a sword. He's not guaranteed to hit, and if he does, as a singular action, it pales to what a Mage can do with a singular spellcast that has no chance of failing on its own.
The weird thing that I don't get is - this isn't exactly NEW NEWS - spellcasters have traditionally (especially since 3e) been radically more powerful than non-casters. This is a real thing.
Plus weapons are implements that serve as an extension of your body and work as force multipliers, but your body itself is a weapon you can use over and over again, even if you don't have another weapon. You don't have an equivalent of that with Spells unless you count unlimited Cantrips, which are really a recent thing in 5e (maybe 4e, can't recall), but don't exist in earlier editions.
They're really not the same thing, other than some spells also being able to inflict damage.
The reason why I bring it up is because Spells are *radically* more effective, yet require no check to execute. The only reason according to you is because "Swords are reusable" seems thin to me based on how people actually play. I'm not sure if you're being argumentative, or rhetorical. I can't count the numbers of pages on this forum dedicated to threads where I've raged about how ineffective non-casters are compared to casters, across multiple editions of D&D at varying degrees... only to find this (and I'm actually giggling as I write this) - that the big win for non-casters is they can keep swinging their swords?... LOLOL this is good.
I'm also not sure how most spellcasting happening in combat negates the fact you can use a weapon over and over again, but spells only have limited spell slots that go away when used. Or how the utility of out of combat spells negates any of this either, or reaffirms the need for requiring casting check on top of spell slots, when all that combat casting ensures you won't have many slots left for utility stuff.
Seriously? When has this EVER been a problem? Even at 1st Level its not a problem. A Magic User at 1st level can still shoot a bow almost as good as a Fighter after he drops his Sleep spell (which ironically would probably stop most Fighters cold). Even now, I don't play D&D and people will rest to get their spells back. This is not a function of mechanical reality as much as it's an emergent form of play by bad design.
I'm not saying you're wrong either - I'm saying you're correct on a position that underscores mine. Spellcasting IS MORE POWERFUL - therefore it's reasonable that it requires a check. That's all I'm saying.
Your contention runs contrary, in appearance, to a many years of lots of people that love non-caster classes.
Even if the utility of out of combat spells is greater than what you can do with non-magical skills (which is somewhat debatable, depending on what you can build using skills) the limited spell slots already serve as a balancing factor. I'm not sure how adding a casting check on top of a spell slot fixes a balancing issue that's already addressed by requiring slots that are limited in number and take a whole night's rest to recover.
Damn, LOL you're serious! Okay you convinced me.
/robot voice Fighters have always been more powerful than Magic Users.
EVERYONE can attack/shoot a weapon. The real difference is a warrior is better at it than everyone else, either by getting better attack accuracy and/or by getting more attacks per round (and maybe Weapon Specialization or something). And also that warriors get more HP, making them more durable.
But a Spell is more like a special ability that you can only use X times a day, like Rage. Only spells are broken down into multiple "Spell Levels" where you get multiple uses per day for each spell level, and can also swap which ability you use for that usage. But mechanically they're essentially a type of X/day ability. Some may cause damage, but they don't work like weapons, which are objects that operate under a different set of assumptions than X/day abilities.
Spellcasters are also not THAT powerful until they hit higher levels. And any vulgar displays of power that occur at low levels (like hitting a group of orcs with a Fireball at level 5) are limited and incidental, occurring only limited times a day (exactly one time at level 5 in older editions) and relying on strategic conditions (Fireballs can fry your group too, and enemies don't always line up in a bunch waiting to be taken out by a single spell), before the wizard becomes a sitting target waiting to get killed by any surviving opponents. And if that wasn't the only combat that day, or enemies had reinforcements coming up, good luck with your dagger, cuz that's all you've got then.
The effectiveness of a Spell depends a lot on the spell and the caster's and/or opponent's level. Magic Missile is practically garbage at low levels in older editions of D&D. It only does 1d4+1 if you're level 1, then you're back to using your 1d4 dagger for the rest of the day. Do I really need to make a casting check to use my only 1d4+1 Magic Missile for that day in order to make warriors shine?
And yeah, low level mages running out of spells can be an issue. I used to play a lot of mages back in the day, starting since level 1 (haven't started since level 1 in ages, usually start at level 3+ now), and they were always a pain and boring AF, cuz they SUCK at direct confrontations and have crap HP. So the moment you run out of your single level 1 spell you become a liability for the rest of the party, even if you can technically risk an attack in between the rest of your group doing all the real work.
Part of the reason I think non-casters are comparatively weak is cuz they get NO cool powers of their own, which IMO maybe they should. Like maybe get a "Power Attack" that works like an actual power and can do a ton of extra damage X/day. Warriors in movies tend to do a lot of martial arts stunts that aren't quite encapsulated by a simple "attack roll" or having higher attack accuracy and more HP.
Another issue might be that while mages get crap number of spells at low levels, the situation reverses at higher level, when you eventually end up with more spells than you can use (plus actual decent spells, as opposed to low level weak sauce), unless you run a LOOOONG session with lots of combat and no chances for rest in between.