Right now it's easily de Jong as Pogba has declined. Both at their peaks is probably Pogba as De Jong hasn't hit his potential yet. De Jong far more consistent.
Different players though, different skillsets, different roles. Funnily enough, Barcelona were trying to shoehorn De Jong into a role that Pogba would excel in, while we tried to shoehorn Pogba into a role De Jong would excel in. You want Frenkie to orchestrate play, to be the guy picking the ball up from the defence and progressing it through midfield, especially with how secure and press resistant he is. It's Modrić-esque. You want Pogba to be used in the Zidane type role, in the opposition's half. You want him to receive the ball from someone like De Jong in the more advanced positions. You want to have the security that when he does lose the ball, the opposition won't be in a great chance right away.