While I have no idea what kind of distributed system would need 7+ 9s, there are plenty of solution providers who at least promise it as part of their marketing. I truly disbelieve that these companies don't have any point of failure within their system that would take them under that threshold, even if it hasn't been challenged to date, but that level of availability is still the published goal. Hopefully needless to say, but 99.9% is not acceptable for most "important" (and yes, advertising is important) applications outside of US-East-1 somehow. Quick examples, no experience with any of these:
* https://www.infinidat.com/en/news/press-releases/infinidat-h...
* https://vindicia.com/blog/9999999-global-system-uptime/
* https://www.ibm.com/downloads/cas/A856LOWK
Bad examples? Certainly yes. Are there any good examples? Maybe, doubtful. Does any system actually need 7 9s? Maybe, doubtful.