Indeed, to me it makes sense in keyboard music to write octaves or other intervals played by one hand on both staves for ease of reading. Of course 19th century composers sometimes extended stems between staves, but I doubt that they ever drew them extending in both directions from beams in the middle. I’d love to see any examples if I’m wrong.
I fail to see any advantage to this notation for e.g. two bassoons. Just as with stems connecting more staves, I can imagine its appeal in hand copying, where line weights are all more or less equal and perfect alignment is elusive. But with digital graphics, the unity of rhythms looks even clearer to me with normal notation.