Let's recap. You made a comment about one person (yourself) playing multiple instruments at once. Somebody replied asking to see that, because it "sounded cool." I provided another example of one person performing multiple instruments at once. Instead of watching the video (or ignoring the conversation), you instead decided to publicly declare that wasn't "real" musicianship, and provided a link to a video where the drummer is literally doing the exact same thing that you just declared wasn't "real" musicianship. You then decided to not watch the video again and instead doubled down on your false claims.

So, if you're asking why we're discussing one-man-bands in a "thread about visual coordination between musicians," that question falls to you, since you were the one who started the sidetracked conversation, which turned out to be a self-aggrandizing advertisement. Yet, now you're gaslighting and trying to make it sound like I did something wrong when, in fact, you were the one who both sidetracked the thread and then confrontationally declared a musician wasn't a real musician, thereby turning it into a "values debate" -- despite obviously meeting all of your requirements for "real" musicianship, since you're both quite literally using identical methods and technologies.

The video visibly shows him playing all of the instruments and not using a sequencer, which betrays that you still haven't actually watched the video.