As far as I can tell, that also changes depending on the world. In my world, everything's starting to go downhill for pretty much everyone because basically anyone with the will to learn and the desire for power is capable of learning magic to some degree. Some very stupid people did something extraordinarily stupid and let something loose that the organization I belong to, as well as a few others, have been trying to fight for the last few years. Unsuccessfully.

I'll admit, the use of foci is common in the less skilled, but I do know quite a few people who can channel magic through themselves. Granted, only about half of them are even remotely human anymore, but hey, what can you do. Magic, at least in my world, has a way of changing a person. [Daniel shrugs, as if it's perfectly normal for such weird shit to happen. (Which to him, it is, but oh well.)]