Unfortunately it has been proven that putting a stupid human face into the thumbnail makes your audience much bigger. It would be nice if YouTube had a “show stupid face” option.
Weird, a grimace in the thumbnail usually drives me away, because it implies overstipulated trivia for teens to me.
The reverse exists, there is the DeArrow extension which removes thumbnails like this and replaces it with a crowdsourced frame of the video.
I like that this exists but I don’t want to use it because i want to know the content creatos to avoid, thumbnails are part of the game, but putting your face on them feels like a cheap trick ( since it’s unecessary ), effective… yes… but cheap…