Ok I think the Magic is like Kung Fu is a poor comparison. I view Magic more like computer programming.
Look at this example, coding is something that needs to be learnt, very very few people can become instinctual coders, if any. They need to at least teach themselves by reading about coding. However what limits coders is their hardware. Humanity's bodies and minds are their hardware.
Some people were born with a powerful computer with incredible processing power, while others are born with an out of date hunk of junk that crashes every few minutes. You could code with either, but it takes a lot more effort to code with the hunk of junk-it's slow and tiresome, and you've got to be careful not to overheat your hardware. And there will just be some kinds of high level programming your hunk of junk will be unable to do, like program a AAA Video Game.
More to the point, anyone who wants to teach you 'coding' will see you only have a hunk of junk, and probably will realise it's a waste of time to teach you. Even at your best, it would take you hours or days to do something someone with decent hardware could do in minutes, so it makes more sense to spend the effort to teach someone with decent hardware. They might not even know how to work with your hunk of junk, because they themselves have only worked with decent class hardware.
Now there are ways to increase your coding ability even with bad hardware. You could have add-ons like external memory or ram (e.g. magic items to boost magic), or you could do some risky self-modification to your hardware to get more out of it (e.g. Lyrium addiction), maybe even canabalise other machines for parts (e.g. Blood Magic). Or you could have a mysterious 'engineer' work on your hard-drive, promising to improve the output, but be careful they don't install a virus (Divine Pacts/Guardianship/Faustian Deals).
But at the end of the day, it's a lot of effort to learn Coding with your hunk of junk. Maybe it would be easier to just use it for taxes, or take up a craft like drawing that doesn't need the computer. Or just get bitten by a radioactive animal. This analogy got away from me.
I would also like to suggest an addition to the magic stuff. The examples I gave in my version were well rounded pure magic. But not every magic user can do all magic equally. I want to take the idea of
Minor Talents/
Adepts and Focused Practitioners from Dresden Files/
Alex Verus to expand the kind of mages out there.
Minor Talents/Adepts have just a single magical trick, maybe just able to see the supernatural, or can tell the future. Some of these Minor Talents are distant distant descendents of a mystical being, or maybe were just exposed to a supernatural event, or perhaps they just have a curse they can't control (Example would be Subaru from Re:Zero). Regardless, they aren't powerful, they can't create spells like normal wizards, but some creative applications of their trick may be possible.
Focused Practitioners are specialists, who can only access a certain kind of magic, possibly due to a mystical blindspot, their mana having an element preference or just natural inclination. Just because one is a focussed Practitioner it doesn't mean they aren't powerful, as their power level can be all over the place. There are many different kinds, such as Diviners, Ectomancers, Sky Mages, Coffeemancers, all with their own specialty.
In order of percentage of populations, it goes like this: Minor Talents > Focused Practitioner > Wizards
There are very few wizards, there's more focused practitioners, and beyond that there's more minor talents. But there are still far more 'normal' people out there, who've never displayed magical abilities. This doesn't mean they couldn't learn, but like the hardware example above, it would be really difficult for them.
Does that make sense?