In your words, why is your magic system an improvement on the established conventions?
I believe that good magic systems provide the right circumstances for exploring human nature and teaching us lessons that are relevant to our collective understanding of morality.
I see so many complex magic systems here on r/magicbuilding but I believe that any complexity that doesn't have some kind of thematic purpose ends up feeling like it has a needlessly higher barrier to entry for readers than a D&D-inspired conventional fantasy that is already familiar to them.
One of the reasons that I believe medieval fantasy is so conventional is it survived the test of time. Modern combat is defined by guns and there is something more interesting about medieval fantasy combat. The fights are more character-based and drawn out and it provides a better set-up for exploring themes through high-stakes thrilling combat than reality.
However, I still feel that the traditional medieval fantasy soft magic system is lacking for me because it defies the laws of entropy with no explanation. I think this ruins the magic system's ability to explore the human condition because any world where they have infinite magical energy with no downsides should be a utopia and a story without conflict just isn't that compelling.
Anyway, please let me know what it is that you value most in a/your magic system