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. (Using translation from Muslim 1639c)  

أَنَّ رَسُولَ اللهِ ﷺ نَهَى عَنِ النَّذْرِ وَقَالَ إِنَّهُ لَا يَأْتِي بِخَيْرٍ إِنَّمَا يُسْتَخْرَجُ بِهِ مِنَ الْبَخِيلِ  

The Prophet ﷺ forbade vowing and said, "In fact, vowing does not prevent anything, but it makes a miser to spend his property." (Using translation from Bukhārī 6608)  

نَهَى رَسُولُ اللهِ ﷺ عَنِ النَّذْرِ وَقَالَ «إِنَّهُ لَا يَرُدُّ شَيْئًا وَإِنَّمَا يُسْتَخْرَجُ بِهِ مِنَ الشَّحِيحِ»