Some weapons scale damage from different things, some scale from strength, others from resilience, from insight, finesse, etc. Also each stat offers different things(resilience offers resistance to negative effects and reduce damage taken, finesse increase dash distance, insight increse spell damage(not sure this one), strength kinda sucks, charm also affects how efficiently can you inflict negative effects on enemies, also for taming monsters, i think there is other things they also do but i don't know.
I think the elemental spells hp also scale from insight, also i think it scales with spells overall(that last part im not sure), speaking as someone that got 10 key framents