[Evgeniuz]

That's not always true. Reader may decide to not use ligatures and the code will appear as is for them. They're entirely optional.

[seemslegit]

This means they need to be aware of this issue in the first place and is yet another side concern to bear in mind, so yeah - externalized cost.

[true_religion]

The reader uses their own font with or without ligatures. There is no cost.