Justice and Rule
Legend
If it turns your sword into a magic sword, it is the result of magic.
And honestly, why not just give the fighter a straight increase in attack and damage rather than turn their sword into a magic sword?
Because a bunch of things require magic to hurt them. All the bonuses in the world don't matter if you can simply strip a fighter of their magical weapon and render them completely useless in a fight.
More than that, the idea that anything fantastical has to be "magical" is part of the problem, because it's incredibly limiting and inherently unbalancing. You box fighters and other martials into relying on magic weapons while casters get inherent power that doesn't need to be doled out by the GM.
"As the paladin falls, decapitated, the cleric runs to his side. With tears flowing down their face, they begin casting a spell and in a flash of light, the paladin rises with his head intact. Weakened, the cleric falls to his knees."
"How did you do that?!" The rogue player asked.
"My deity saw my faith and answered my prayer. With divine intervention, they were able to heal."
Vs
"As the paladin falls, decapitated, the rogue runs to his side. With tears flowing down their face, they begin to pull out their surgical equipment and in a few moments, the paladin rises with his head intact. The rogue swipes sweat from his eyebrows."
"How did you do that?!" The cleric player asked.
"Oh, I'm just really good at medicine."
...
Nah, sorry, can't do it. That'd just kill the moment.
Actually I think it's pretty damn awesome if someone went "How did you do that?" and he turned and went "I'm the best damn surgeon in the world". It's just as cool if not cooler than "Welp, just going to use my spell slot here to raise you up no problem". You can put all the fancy words behind it, but actually putting a skill check on it is way more exciting and rewarding because it shows the strength of the player and their expertise than just "Ah, well, I have this spell slot I can burn..."
And this is where this kind of opinion is going to be holding martials back from being interesting: you can describe anything as being fantastical, and when you only let magic enter that realm, you pigeonhole martials into a tiny box compared to the open world that magic allows for. It's just the wrong mindset and no amount of "reliability" is going to make martials catch up because you are limiting them to the mundane no matter what.
This is what I mean, yes.
90% of spells that inflict a status on the enemy requires a save.
A lot of spells require sight.
A lot of spells require targetting.
Commune has a chance to fail.
Teleport has a chance to fail.
Power Word Kill can fail.
Gate can fail.
Illusions can be seen through.
There are wards, barriers, and areas that can cause spells to fail in general.
There are spells dedicated to making spells fail.
There are many ways spells can just not work, but those spells are considered "bad" because they aren't guaranteed and only the spells with extremely good effects are even considered.
Apparently, we can't buff the martials. There's a certain threshold people are willing to let martials be buffed before the casters start having a fit.
And maybe we shouldn't baby casters. If they want to be able to control the fabric of reality the least they can do is understand that power comes with drawbacks.
And attacks can miss, be resisted, and even completely negated. To act like magic "fails" misses that it is often more likely to succeed given that DCs in the system advance while saves do not necessarily. Furthermore, you actually have the chance for amazing things with those, while even an assured Athletics check will only get me so far. This is just going to turn into Angel Summoner and BMX Bandit all over again.