The case against conversational interfaces

To me natural language interfaces are like the mouse-driven menu vs terminal interpreter. They allow good discoverability in systems that we don't master at the cost of efficiency.

As always, good UI allows for using multiple modalities.

Yes, this is exactly it. For things that I do rarely, I would love to have a working natural language interface because I know what I want to do, but I don't know how to do it. Even if there were more efficient ways to achieve my goal, since I do not know what they are, the inefficiencies of a natural language interface do not matter to me.

In this sense, natural language interfaces are more powerful search features rather than a replacement for other types of interfaces.

I feel like chat interfaces have terrible discoverability. You can ask for anything but you have no idea what the system can actually do. In the menu system the options were all spelled out - that's what discoverability means to me. If you spend enough time going through the menus and dialogs you will find all the options, and in a well-designed interface you might notice a function you didn't know about near the one you're using now.

What chat interfaces have over CLIs is good robustness. You can word your request in lots of different ways and get a useful answer.

Yesyesyesyes! I do wish I could think of more examples supporting both well.

VSCode is probably the best I can think of, where keyboard shortcuts can get you up to a decent speed as an advanced user, but mouse clicks provide an easy intro for a new user.

For the most part, I see tools like NVim, which is super fast but not new-user friendly. Or IOS, which a toddler can navigate, but doesn't afford many ways to speed up interactions like typing.