I want to know when YT made it possible to have thumbnails be their own image and not taken from the video itself. I can scrub the video through every single frame and never actually find the thumbnails anymore.
Hell, sometimes the text in the thumbnail says something that isn't even discussed in the video at all. Those are the ones I hate the most. And I wouldn't necessarily want to remove the thumbnail, just because there are plenty of channels that make the thumbnail the actual title and the title is just... Bullshit, non-descriptive, a number, etc. Not all of them are bad. Civvie 11 and Internet Comment Etiquette do this. Erik probably does it on purpose both for the fact it works and also because he is a satire channel that regularly shits on these practices by showing how dumb they are. Civvie also satirizes YT's bullshit, but that's not really the prime focus of the channel.
For specific types of video where they are mostly similar looking (For example, online TCGs and such), it can be hard to get a thumbnail you want that looks different than other videos of the same type, so people were adding long segment with the static image of thumbnail they wanted at the end of the video for a workaround, until Google finally relented and just let people use the thumbnails they want.
I don't have a problem with this, I just try not to watch videos with clickbait thumbnails and/or titles, because if they think they "had" to do that, then their content usually isn't very good to begin with.
I think it's really telling when creators have different thumbnails on Nebula vs YouTube. It could even be interpreted as a scream for help "this is the thumbnail I wanted but this is the thumbnail that puts food on my table"
I suppose to drive engagement with fake thumbnails, the same thing they do when they put irrelevant things into your search results (thankfully that one is easily blocked by a uBlock filter).
True, but even if YouTube forced you take a screenshot from the video people would add the image in the last frame similar to what they sometimes do for YT shorts.