It does not (necessarily) bring good (in the form of substantial, and tangible results), but it is the meant whereby something is extracted from the miserly persons.
عَنِ النَّبِيِّ ﷺ أَنَّهُ نَهَى عَنِ النَّذْرِ وَقَالَ إِنَّهُ لاَ يَأْتِي بِخَيْرٍ وَإِنَّمَا يُسْتَخْرَجُ بِهِ مِنَ الْبَخِيلِ