Often you just want to send a few buttons to the user to choose from, and being forced to add text before this means there is no option but to send what is often unneeded words/messages. Allowing these cards to be sent without an actual question would add so much more flexibility and allow much more seamless conversation design

It already works with Raw Input, so it should be possible with Single Choice also.

It can't show anything in the Webchat that doesn't have text in it

yes