I remember reading about it, once when I started learning ReactJS; and never until now have I had the chance to come across it, or use it myself in code.
Have you had the chance to use it somewhere? What was the use case?
Simple. Whenever you need to parse HTML from any source in an component. The naming makes it more dangerous than it actually is. Just keep one thing in mind: Do YOU control the HTML String that's being inserted or is it from User Input? If you control it, use it wherever you want, if not, you should to some sanitation before adding it.
And the naming scheme remembers you of that ;)
Greets
Juho Vepsäläinen
SurviveJS
I've used it in static site generation (injecting HTML generated by a Markdown parser). As there are better solutions now it would be possible to avoid that. But since it's totally under my control the security issue doesn't matter (no way for someone to inject code without going through me first).
It's particularly dangerous if your users can inject the data as then you literally have XSS vulnerability in your application. Instead of injecting pure HTML you probably want to have some intermediate format you control in between (say JSON that's mapped to React components). There's a good reason why it has been named the way it has been.