Unity became usable in recent releases. But I've never been 100% comfortable with it, I've always felt like I'm interacting with my computer through a bowl of treacle. I've been using Ubuntu Mate for a few years now, I much prefer the old Gnome 2.x look and feel. And with compton it's lightning fast
Yeah the problem is it's not even proper desktop interface, it was made for touch screens i.e. tablets, also 7 years ago ubuntu was first distro on distrowatch.com hits per day ranking, today its 4th and it really goes down every month, so I'm assuming it has something to do with Unity and pragmatically it was a fiasco that was bringing Ubuntu down, I also doubt they can do much about it at this point in time.