In my case I do actually need to use Open App, because (1) the Steps compilation on Galaxy watches is currently broken - it doesn’t show the complication icon. (See this thread.)
And (2) I want the steps functionality to be hard-coded and automatically working on my watch face, without the user having to select a complication for it to work. That’s also the primary purpose of being able to use the [SC] tag in a text field, and the primary purpose behind the Open App action menu. And as I’ve explained above, it’s illogical that heart rate is provided on the Open App menu, but steps is not, yet I can display both of them via a tag in a text field. 