You also get critical hits with your +2 to hit mage trying to attack an ogre with a dagger or a nat20 to sneak when your full-clad armoured clanky half-orc companion tries to sneak past the dragon. And they succeeded.
You see it as a possibility of failing, I see that as a possibility for your unskilled character to be able to succeed in a way that would not be possible if you do not roll. In real life, it also happens like that. Nothing is 100% ruled and sure, fit to a standard, with predictable moves in a black and white canopy.
Sometimes David makes the goliath fall with one lucky shot of the sling, sometimes you cannot hit a barn from ten paces with a bazooka because of a sudden wind that offshoots the projectile.
That is why I dislike chess and why I like dice games.
Very true, you can get lucky and roll 20's, but there's a 95% chance of that not happening. One thing i didn't think about is their use of 'Inspirations', It could be they provide X number per day or something on the easier difficulties and given the recent gameplay, even normal assuming thats what he was playing. They may target rerolls as a reward. a buff itself, instead of changing other things for difficulty. Hmmm....interestiing
So instead of giving a monster a debuff to stats or attack chance, they'll just give the player the ability to reroll, perhaps with the easiest being infinite rerolls.