> has journalctl -xe ever dumped any useful information for anyone ever

It can be useful when there's potentially multiple things leading up to the error in whatever you're running, as it is showing and explaining nearly every action that's recently happened in the system log. But if you're just wanting to look at logs related to nginx starting at the most recent then just query for niginx's system log instead of the whole system.

    sudo journalctl --pager-end --unit nginx

or:

    sudo journalctl -e -u nginx

or:

    sudo journalctl -eu nginx