I tried to watch it, but I got bored and stopped partway through. Not really because I thought it was a bad video, but because I didn't get any of the references or know who any of the people in it were. Except Will Smith, him I recognised.

Does it deserve to be the most downvoted video in the history of YouTube? It's certainly not the worst video on the site, not by a long shot. But to reach such a number of downvotes, a video needs to be extraordinarily popular in the first place, and then piss off a large number of registered users. (Registered users are key, since they are the only ones that can vote on a video. For all we know this video could be well loved by Twitch users and Fortnite players, but hated amongst the YouTube creators community.) And then sadly starts the bandwagon effect, where everyone hates it just because everyone else hates it.

On the other hand I can't recall ever hearing of YouTube Rewind before, but all the noise surrounding this year's video made me look it up. So there's that.