Main concern is balance in my opinion. Under the 20Mainstat cap for +5 Attackroll Modifier it devalues Statpoints alot. A "small" +2 Bonus is valued 4 Statpoints. But when you are maxed out and hardcapped at 20 the +2 Bonus will very strong like a second Bless spell. That mechanic in my opinion very prone to Min Maxing to reach you cap of 20.
Thats a generel problem with D&D. You have no peak you have only a cap.
Its literally useless to use a weapon without Proficiency.
And thats absurd because when i switch to a Warhammer to inflict damage to Plate wearer because im not reliant to hit the small weak spots i dont hit him easier and without Proficiency only worse.
And at the same time you cant be a "tin opener" which has Proficiency to kill armored targets.