A less drastic extension is Clickbait Remover. It replaces thumbnails to an actual frame from the video and de-capitalizes titles: https://addons.mozilla.org/en-US/firefox/addon/clickbait-rem...
Which should be done anyway. YouTube dropped the ball on that one.
Older YouTubers used to manipulate this by putting the suggestive part of the video at the right time.
Here's a blast from the past doing just that: https://www.youtube.com/watch?v=r8tXjJL3xcM