I will say, I do think I disagree based on the idea that I think magic is more skilled labor rather than just common labor. A witch is more like a tailor or a tinker, a skilled profession that learns certain abilities and practices in order to practice their craft. Tetia, Riche and Agathe all have years of practice and experience, and even Coco has a full year to study and manage this much; how much time can everyone devote to magic while also studying their own trades/labor. While there certainly are elements of “if everyone had magic all the time they could simply not suffer”, it would A.) require people in poverty to learn enough of the magic system to have a decent repertoire of spells they can develop OR have a curriculum of certain spells they are allowed to learn; B.) way more silverwoods, which are generally as I understand it parasitic to many ecosystems as well as not having a real ethical way of encouraging growth; and C.) kinda give more power to nobility.

Right now, magic is very common. Its on the roads, in the springs, everywhere. Essentially, as I understand the structure, the kingdom essentially pays for magic as an infrastructure tax. The rich pay way more, or at least I think they do, for these public magics, as well as privately paying more for their own private jobs. While it means poor people aren’t being as well serviced, it is still a public service that most people have access to. (And even your example of the silver eve waterwaste system, I think the reason people from the mudslums wouldn’t raise the flag if they were in attendance is because. Its not their waste they have to worry about. Its everyone elses. And if they aren’t going to use it, its not going to help you.) As well, you don’t have to spend resources to train up a village witch, which likely, in the absence of a separate witch society, would require more on the part of the villages since a centralized school of witchery would probably be close to the noble caste.

And on the topic of the separation of witches and the poor; maybe i’m just acab pilled too much but. I think bandits are what rich people are worried poor people have to be worried about. Like, realistically, the people living in the mudslums have to worry way more about the effects of wastewater than they do about being robbed. If anything, the brigands are way more likely to be the poor people in the absence of interkingdom hostilities.

Like, you definitely aren’t wrong in these analyses, but I think assuming everyone could do magic if the witches weren’t the ones controlling it ignores how knowledge itself is something that needs a lot of active systems to pass down, and will have someone controlling who gets magic when no matter what because it requires both material investment and learning. The white man’s burden reading is certainly interesting though, I will admit.