Quartz
Hero
Stat bonuses and proficiency bonuses are in the same ballpark, so could we just replace the former with the latter?
For instance, being Proficient in Str would let you add Str to your attack and damage rolls, while being a Fighter might bump that to Expertise. Being Proficient in Con would give you bonus HP (= HD * Prof. Bonus). Hit points would be as now. Similarly, being Proficient in Int would let you add your proficiency mod to the DC of arcane spells whereas someone not proficient (a dabbler like an Eldritch Knight, perhaps) would not. And so on.
Characters could gain stat proficiencies as they advance.
For instance, being Proficient in Str would let you add Str to your attack and damage rolls, while being a Fighter might bump that to Expertise. Being Proficient in Con would give you bonus HP (= HD * Prof. Bonus). Hit points would be as now. Similarly, being Proficient in Int would let you add your proficiency mod to the DC of arcane spells whereas someone not proficient (a dabbler like an Eldritch Knight, perhaps) would not. And so on.
Characters could gain stat proficiencies as they advance.