I've got no need for it; AdBlock does a wonderful job, and as far as I know, it's functionality is unique.
My question has nothing to do with AdBlock's functionality, rather it's Safari's functionality I'm questioning.
That is certainly a legitimate question. I use 1Blocker/1Blocker Button and "Enable Content Blockers" in Safari 11.0.1 makes a significant difference on many sites. It is sometimes the difference in a correctly rendered page and a blank window or just text running down the left margin, or even more often whether clicking on a link will work or not.
I don't know the details of how AdBlock
vis-a-vis 1Blocker, but this seems to be a subject worthy of further exploration.