I'm not disagreeing with the reasoning, as it's one of the basics no matter the DC at decent level, and I do think Purify is a problem for the exact reason you mention, but I think you still conveniently forget everything else that happens between successful insta KOs bursts, like smaller burst attempts, harassment, primary target rotation, failed bursts (those are legion even on the video), etc. I don't think all of this has no inherent value at all.

Also, what metric are you using? Something arbitrary? (I really, really doubt that JP unranked is equal to NA/EU diamond lol)