I haven’t got a stream deck yet but will eventually most likely. I see the main advantage being no need to memorize anything. Dorico is a program that pretty much requires you to use key commands. They are not really optional shortcuts. So the stream deck removes the need to memorize them. I might get one for my senior Mom who can’t remember stuff like that.
For myself I plan to memorize the dorico key commands anyway, but one thing I don’t like is that an awful lot of the keys needed are key-combinations, which I find dreadfully difficult to memorize: wait was that option s or command s I can’t remember now. Also I wish I could sit at the computer with my fingers on the keyboard and just start typing music like a typewriter. I think that can be done now but some of the key combinations make it kind of klunky and I personally have to look down to find some of the modifier keys. So at some point I am going to try to change some of the key commands so that all the important stuff can be done with either a single key or at most with the shift modifier, which is still in line with a QWERTY typewriter.
At that point I’d rather work without a stream deck. But between now and then is a good time to have buttons with pictures on them.
I could also see it as a useful place to put custom macro buttons