This is how in brings better typography:

Discretionary Ligatures (dlig) – sometimes called Rare Ligatures – also connects characters like Standard Ligatures but work on not-so-common ones, like “ct”, “st” or “Th”.

Discretionary Ligatures are usually more decorative in nature, and should be used at one's discretion, thus the name. Some of these ligatures may also be common in the distant past, and could be used together with Historical Forms.

A font that have this feature is EB Garamond. Try them with text like Extract, Chest and Thedore.

You may also be interested in liga, hlig and hist.