If your group has the trust
This is the heart of tons of table drama. The DM wants to tell a story and the players want to be heroic. The dice add randomness that can add drama, but they also cause chaos by introduction outcomes people don't want.
If you're just trusting the DM, why have rolls at all? Just tell GM what you're doing and GM tells you what happens. But then players feel like they've got less heroic agency. They're not pulling together a brunch of cool traits to do something risky and daring. They're saying "I leap over the battlement and drive my spear into the champion's throat" and the DM either says "Yeah" or "Nah". You need phenomenal trust in your GM for that to work. A bunch of 12 year olds at a table aren't going to have that.
Let them handle the mechanical elements of the game so the players can focus on the role play.
The mechanics are, ostensibly, there to facilitate the roleplay. The paladin's smite isn't just a set of numbers, it's an expression of their role as holy warrior and divine judge.