Nose tackles don't often get sacks but they collapse the middle of the pocket preventing QBs from climbing up the pocket to avoid the outside rush. So guys like Burns will get more sacks because QBs have to readjust as they have to retreat or move around in the pocket taking their eyes off downfield. Plus they take on doubles to give other d linemen one on one matchups.
Vita Vea is considered one of the top nose tackles in the league and has 66 pressures in 3 years. In 2020 he had 2 sacks and in his 3 year career he has 7.5.
Brown in his rookie year had 2 sacks and 19 pressures without much help. That puts him in line with the best nose tackles from a production point of view.