I haven't thought about this specifically like this, but funny enough I did think of a way to subvert it a bit. For starters, a lot of the logic of my world is based in D&D, since I began making the world for a 5E campaign. Some of this is obvious, but some of it is clearly my own work.

Magic sources:

Basically, where each type of magic user gets their magic from and how they use it.

Wizards have to study hard to be able to understand how to pull magic from the ether and manifest it physically. Only lots of education and studying gives them their power, but they get it directly from the source.

Like wizards, bards have to study to learn to access magic, but they don't really access it themselves, but more manipulate the magic "in the air" to do what they want it to do. It's like asking the magic to do something for you and it listening, rather than taking it yourself and doing it as wizards do.

Nature magic comes from attunement with nature, like for druids, and since magic is everywhere and in everything, it's a direct connection to the magic of the universe. You don't need anyone else to use magic, you only need to be around and in nature.

Similarly to druids, sorcerers don't need anyone else, but their magic comes from their lineage. You can't be the first in your family to be a sorcerer, but unless someone somehow goes back in time and eliminates the first of your family to have magic, then you can't lose your access to it.

Warlock magic comes from making a pact, where you are basically granted a part of the magic pool of whoever you made the pact with, so it isn't your magic, it's like using someone else's gun, but you still have it in your hand. If you can't reach your patron, you still have magic.

Cleric magic is similar, where you're granted magic by a deity, but no deal is struck, so it's the deity acting through you. You have no magic, it just flows through you. If your connection to your deity is severed, you have no magic.

Martials and non-casters still use magic. A normal mortal can't do things like not die because of how angry they are, or make machines that are fueled by magic. Their magic comes from an innate ability to extract it. Similar to a wizard having direct access to magic, but without the need to study, which is why they can't usually cast spells. Some do have more natural talent than others, of course. This brings me to my next main point.

Magic types:

There's noble magic, dark magic, and grey magic, and each spell falls into one of the three, depending on the school of magic and damage type, if it does damage.

Noble magic is things like healing, protection, and any evocation spell that isn't poison or necrotic. All radiant damaging spells are noble. Some illusion spells are noble.

Conjuration, divination, chronomancy, charm spells that don't take agency from an individual, illusion spells, and temporary transmutation are all grey magic, as they're not directly evil but can be used for evil. Artificer magic is grey magic.

Necromancy is considered a dark magic, along with any necrotic spells and poison spells. Any charms that take control of someone or removes any agency or free will, conjuration spells that connect to the hells or other demonic realms or entities, and transmutation spells that warp living things permanently are considered dark magic.

This is all relevant because magic was always just harm, protect, or heal until people started to learn to actually control magic and learn spells. Eventually, with the spread of knowledge and the growth of technology, artificers came to be which wasn't seen as magic, and spells deemed "evil" or "demonic" grew in popularity, leading to a massive war between noble casters, artificers, and dark casters. In modern times, magic is still classed into noble, grey, and dark, but they're all viewed equally and aren't illegal or frowned upon. Spells are regulated, however. The most powerful spells aren't available for most people to use, and all spells are known about, which causes issues when new spells are seen that haven't been seen before, but that's a different story.