As of the Spring '24 release (February 24), users can review, choose, and merge potential duplicate contacts efficiently using the NPSP Potential Duplicates Lightning Web Component, which directs you to the NPSP Contact Merge page.
The standard Lightning Web Component for Potential Duplicates is often used by charities and this is why you might have a heap of Empty Households.
Watch the video - there is a Gotcha at 1:12.
