They have already done that with Loaded Dice.
I'm fairly sure that if you do 10000 rolls with Loaded Dice on or off you will get the same success rate. Loaded Dice only makes your RNG better after a failed roll, no?
What I'm proposing isn't that.
No, basically you are eliminating the need to roll for probably over 50% of the ability checks. Even with the +10, you still had to roll back in the day, it just made it more likely to succeed. But there was always the chance that you could just roll unlucky. Say a saving throw was 15, you had a +10 modifier, and you rolled a 1, you still lost the check.