I agree, but Andrew makes a very careful distinction between leaders (in the sense discussed in the video) and bosses, and correctly identifies that there are still risks of hierarchies developing out of anarchistic leaders. One of the YouTube comments makes a point that a better word for Andrew's concept of "leader" in his video would be "guide". For talking about this concept in English, I agree with that commenter, but otherwise I also agree with Andrew's take.

this specific video was reuploaded to peertube https://anarchy.tube/videos/watch/6291f727-dda3-4093-8e67-f28283dca9a6

which is honestly a lovely praxis. more youtube videos should be mirrored over there.

I like https://inv.nadeko.net/ because it gives you several backends to choose from.

Do you not wish to use a mobile/desktop app, or can you not use them?

The thumbnail is using the political compass as a way to assign well known personalities to political ideology. Lenin for authoritarian left, Trump for autoritarian right, Elmo for liberarian right and ?/nobody for libertarian left. We could discuss these placements, but the main point is that for libertarian left aka anarchism there is no leader assigned

Also thumbnails might be different for different users because of A/B testing from YouTubers or just normal updates/changes to the video by the creator