People read by the overall ſhape of words, and given that the long s is an aſcending letter, it gives words a much more varied ſhape than the evenneſs of only uſing the round s, which aids in reading at a glance or taking in lines of text at a time ; and while it is anecdotal, I’ve been told that it helps ſome people with certain reading difficulties ſuch as dyſlexia becauſe of that more varied appearance it gives words and lines. Furthermore, while it doeſn’t really apply to Engliſh, ſome languages uſe word-compound or ſyllable-baſed rules for the long s (an example being German), which can actually help tell ſome words apart from each other ; for example, wachſtube and wachstube (guardhouſe vs tube of wax) or Kreiſchen and Kreischen (ſcream vs ſmall circle) can be eaſily diſtinguiſhed from each other even without context with the long s where they would need more context without.