Having moderation is not the issue; having moderators who read the item is. Most sites have too few human mods, this is why your item can languish over the weekend when your Mod takes the time off.
In ancient days, when there were a slurry of sites, people would post the same item on two or three of them. The first site that posted meant the others missed out. Often, one had enough time from the posting of the article on Site One to race to Site Two and change it around so that a plagiarism checker would miss it. Sometimes, one even could reach Site Three, because moderation was so slow.
I once had a very hot topic, posted it on site 1 and after an hour, put it on site 2 where it was pulling in hits. A day later it was still ‘pending’ on site 1.
I wrote an article about the slow moderation of Site 1 it on Wikinut, (when Wikinut paid) which got the Owner of site one in a snit and he began writing comment after attacking comment, and that article went viral.
However, returning to the point, without a human reading an item, or having A.I. as moderator leads to the publication of rubbish.