WayOfTheFourElements
Hero
But the current system still allows for trap choices. If someone builds a fighter or rogue with 8 Str and 8 Dex, thinking that they want their character to be a charming investigator but none of the other classes fit, the character is not going to contribute in combat regardless of their other stats. Decoupling ability scores from offensive capability (at least directly) broadens the kinds of characters people could play.
I didn't mention decoupling from race. You could easily still have racial ability score bonuses along with this system. Wood Elves are agile and perceptive. High elves are agile and intelligent. But Orcs can be wizards too, and a 10th level orc wizard is as good a wizard as a 10th level high elf wizard because they're both 10th level (the orc wizard likely has different talents than the high elf wizard).
I would totally play the 10 STR, 10 DEX investigator rogue. Sounds like fun. I'm not the best swordsman, but who cares when I can use other skills to solve problems. Adventuring isn't all about combat.
Playing a dumb wizard can be fun, too. Who care if your save DC sucks. Not all spells have save DCs. I'll concentrate on those.
Optimal isn't always synonymous with fun. Though it can be for some players, others prefer an uphill battle.