Those three books are called the Broken Earth trilogy, starting with The Fifth Season, and it's probably my favourite trilogy. (Not correcting, just adding detail so they are easier to find). The magic system here always feels very specific and 'grounded' (heh), so it doesn't feel like the fluffy magic of more "high fantasy", and maybe connects more with sci-fi sensibilities? Anyway, i agree that it's excellent.

OP could also look at Ursula Le Guin. The Earthsea books are amazing, very low-key and character focused. More in the fantasy space too though, but so is Dune pretty much. She also has Left Hand of Darkness, which was great and more on the sci-fi side (no actual space travel or other planets, aside from references), particularly if they have any interest in a kind of meditation on cultural differences and gender.

Ugh just read Fifth Season and am reading Obelisk Gate now. Just SO good.

Can recommend The City We Became by them. Not entirely flawless, but I rattled through it in no time and was plenty good enough for me to go out and buy the second in the series (i think of two).