But keyboards are not. Even if I’d be able to convince the maintainers of my favorite programming language to also accept some Unicode glyph as synonym to ‘==‘ how do I type it?
Ligatures might not be ‘the right’ solution, but they are a highly efficient approximation. Also the cost of reversing the decision to use them is basically zero.
That's what I said. To the programming language it's just a token and representing that with a single ligature is fine.
I replied to a comment, that the document is character-based and therefore ligatures are inherently wrong.