Many biggest sites use KVS. And they have been doing this for over 10 years.
KVS development has never stopped since 2009 and it's not just words - the whole story is visible by the following link -
https://www.kernel-video-sharing.com/en/news/
Our clients can even influence the development -
https://forum.kernel-video-sharing.c...0-development/
And finally some examples - take a look at one of the leader in website building -
https://adult-html.com/ - more than 90% built on KVS!