Part of losing that "shine" is them abandoning Unity and other Ubuntu-specific things. Back when it first got popular one of its selling points was how easy it was to install the proprietary nvidia driver. It always had something a little extra compared to other distros. Now it's using the same stuff as everything else and meanwhile I've ditched nvidia a long time ago and now even Gentoo is as easy to install (for me at least) as Ubuntu was back then.