Mystic_mammoth

I would hazard a guess it has something to do with firstly Intent, which is a fundamental principle behind applying investiture meaningfully in all forms and worlds, and secondly, Kaladin's already far developed healing ability due to his intimate knowledge of human anatomy, healing and surgical training which allows him to focus the power of stormlight to do its work more efficiently. After all, magic on Roshar operates by enhancing present or innate abilities rather than granting new focused abilities. Surgebinding works with what it already there. I would even theorise that the specific abilities that manifest in radiants are related to innate or already present abilities. This idea in combination with the more focused Surgebinding skill masyered over time by slow and arduous process of oath progression, makes Kaladin a far better healer than Szeth who simply received his powers from a powerful sword.