Its syntax [1] is also surprisingly powerful. You want to block an element if it doesn't contain an element matching a particular string/xpath/css selector? But only on specific pages? Even if the URL is manipulated by .pushState? Easy.

I've also used it to blur the text of newsarticles talking about a particular sports event.

Frankly that part of the extension on its own is amazingly useful.

[1]: https://github.com/uBlockOrigin/uBlock-issues/wiki/Static-fi...