I probably should have explained this earlier, but better late than never!
Something that has always bothered me about standard system novels is that the main character never really 'owns' their power. It usually comes from an unexplained source or some ROB. And the power it gives always feels illusory to me, like it's fake and it can be taken away at a moment's notice. So I wanted my MC to truly own his system, having created it himself by sheer luck(lazy writing).
Because of that, I can't have the levels work the way they do in a lot of other system stories, where the system is basically all-knowing and already understands the absolute ceiling of every subject in the world. This system doesn't. It can't instantly know the absolute ceiling of a discipline; it only senses potential.
And because the system is completely owned by him, it gives him all the power it possibly can. It doesn't dangle rewards in front of him like a carrot on a stick.
That's why 'Level 10' isn't the absolute cap of a field, but rather the amount of data needed to compile a Passive Skill. If a field has high potential but humanity hasn't explored it enough yet, the skill can't reach Level 10 or synthesize until the MC (or someone else) actually pioneers new knowledge to fill in the gaps.