Again, you're underestimating the careful care a (good) bartender has to follow when preparing for drinks. Say for instance, the recipe calls for lemon juice. A typical implementation of a robot would be to have lemon juice prepared earlier, but that has different taste profile to freshly juiced lemon. Then ok, let's have a juicer... except are you going to also roll the lemon carefully first to bring out the juice and flavour before cutting it carefully for the wedge? Or are you going to shred/press it? How are you going to do careful presentation work on the slice, like zesting it? Carefully pinch the skin to bring out the oils from the skin, but not actually put it in the drink?
And hell, that's just lemons.
I can't imagine having machines that are yet delicate enough to do this quickly, that are also small enough to fit in a bar, as well as being so versatile. Most likely, for a while yet, only humans can do the task considering how delicate the work is.