I had another solution that used Ublock Origin Filters that seemed to break. Found this and it seems to work. No more accidentally clicking that needlessly large warning that fills a third of video thumbnails.

I was so tired of accidentally hitting this button. And every video from youtubers with more than 200k subs is sponsored, so it is useless. Really happy I can use this to remove it.

Amazing extension. Works exactly as it says.

It doesn't work. Installed, checked it was turned on, closed firefox, restarted computer. There is still a banner, not sure why this has 5 stars, don't waste your time until it is updated. Version 1.0.2

Does as it says

Does what it says. Removes the paid promotion thing from covering 20% of the video thumbnail (stupid ik)

Great. It works