I don't know if it is still the case, but as little as three years ago I tested various Linux distros for someone else to run on a laptop computer. Stuff that is easy to run and easy to update. I wanted to try OpenSuse. It kinda failed me in that it had obvious bugs. Too many of them. Bugs that could be fixed and all (Linux), but nothing an end user should see. I tried a couple other ones, but in the end, Ubuntu proved to be what it has been for more than a decade: A true Linux for end users. Since I prefer KDE I went with Kubuntu.
Then last year, LXD became the perfect solution for one of my personal user cases. I have been running Xenial ever since (btw. shoutout to Stephane Graber, one of the major driving forces behind lxd), even though I have been a 100% Debian guy for almost two decades now.
I don't know about embedded, but I heard they put something out for smartphones that was pretty rad.
And yes, Ubuntu wouldn't be possible without Debian. I am typing this on a Debian machine, of course.