That’s what I just said in both of my posts.
But that people only use them as single items is not true.
Just to make it clear, I fully agree that set items are not in a good and exciting place currently, but there are some that see some limited use. (Which sets are very bad and which are at least good within a specific niche is a entirely different discussion, that could be opened)
Now to come back to the original point of the topic.
With the addition of legendary items, the gap from exalted items and uniques to set items will become even larger.