This extension is useful but please add these features:
1. Blur thumbnail instead of hiding option
2. Show the video duration while blurring thumbnail
3. On/off keyboard shortcut

This is exactly the extension I was looking for. I watch a bunch of youtube channels & videos with "scary" content, but i tend to hate the thumbnails that go along with them (the clickbait-y trend for ~scary~ videos being what it is - "find the most disturbing visual & distort it into something even less pleasant to look at"), which makes it a slog to scroll through some of the channels i actually enjoy! thanks to the developer for making this add-on available, it works well & makes youtube a more accessible site to navigate. 5 stars

Way better than what i was expecting. Over the years, i have developed a bad habit of going to youtube when I get stuck on a tough problem or just unconsciously. I noticed that the thumbnails where a huge problem because they were the main reason for me picking a particular video. I wanted something like this to deprive my mind of the colorful thumbnails that it uses.

Thanks. This is really helpful.

Great! the only thing missing is a button icon to place on toolbars ("customize"-friendly), to turn it on/off.

Does exactly what it says and shows on the screenshots. Man what a relief for the brain

Thanks a lot @domdomegg!!! This is exactly the FF extension I needed to slow down my Youtube-ing....

Thank you, works great!

Thank you so much! It makes so much sense!