This is how in brings better typography:

Historical Forms (hist) brings your text back to the distant past, like in 1800s. It replaces some letters with their archaic alternatives, such as the long form “s”.

It's worth to note that some historical characters have quite complex rules that may not be implemented completely. For example, EB Garamond doesn't reserve the round “s” at the end of a word (try “sinfulness”).

Technical-wise, Historical Forms only deals with single characters. For completeness, consider applying the Historical Ligatures and Discretionary Ligatures.

A font that have this feature is EB Garamond. Try them with text like substitute and Joiner.

You may also be interested in hlig and dlig.