Any sufficiently explained magic is indistinguishable from science.

Which is why I don't really agree with his soft/hard magic division. Hard magic isn't magic at all. It's macguffin powered science. Magic is supposed to be mysterious and mystical imo. It can't exist on a 'hard' scale. If I fully understand the rules and 'systems' behind 'magic' there's nothing magical about it. It's a bounded system that has become a fictional science.

Which isn't a bad thing. I can see it's appeal and like plenty of books with such things, even Sanderson's. I'm just less interested in it and generally not as impressed by munchkinry as others and find the soft/hard magic concept to be an explanation in search of a concept rather than a useful division.

Honestly, if you want to see a marvelously made 'magical' system with clear rules that maintains mystery and mystic qualities, read Wildbow's urban fantasy (Pact and Pale). The ways he writes Practioners is a highlight of some truely excellent world building, and harkins to the kind of magic you'd see in Shakespearian theatre built on pacts, oaths, and traditions rather than a fantastical conservation of thermodynamics. It strikes a great balance between magic being explainable but still mystic because it mostly runs on the momentum of 'this is how we do it and we've always done it this way so follow the proper procedures!'