I'm gonna go down in the flames here but Unity was great. It was very stable for one thing. I never had an issue that I do with literally every single other DE that exists. XFCE is stable but customization is a time consuming affair. KDE is riddled with bugs. Cinnamon doesn't get enough support and thus has issues with various software (recently like not being able to run Factorio via steam or having bloated font in KeepassXC), and GNOME is like a happy medium between KDE and XFCE. Unity just worked. Out of the box like Windows and MacOS. It made me sad cannonical decided to drop it. It was the first real dedicated support to a DE that Linux decidedly needed.