Its not evident to me what this does... It says that it "prints per query and average metrics", but it seems to just output some extremely generic stats. Does "query" actually mean request here?
I see there's a wordpress-specific wpdb mechanism - though it just seems to report total time spent on queries, and the slowest query. Surely something like Query Monitor is a far better tool for that?
A tool that everyone should be aware of and using is php-spx - its absolutely glorious for performance profiling/investigation. xhgui is similar, but bulkier and (in my experience) less accurate/insightful.