I think this is the right frame of mind. RPGs already abstract away the player from skill-based outcomes by having virtual representations of condition -> HP, kinetic force -> STR, knowledge -> INT, and all those other shortcuts D&D originally used to make wargaming appropriate for individual player characters. (Of course then it also gave us 2 dice rolls to get to the result, so...) This is in stark contrast to something like an arena shooter or other realtime game in which human reflexes matter much more than some arbitrary stat.
Adding a % dice roll on top of already-abstracted stats is too much of a gap between the player input and system output IMO. For every dice roll attack there should be some contextual or situational way to make that attack 100% accuracy, whether it's flanking or a passive skill like vanilla's Concentrate.