Indeed.. I have been a Ubuntu user for some time, but have recently switched to KDE due to the latest Ubuntu desktop experiments which really put me off. After installing KDE Plasma, which I thought was a single DE, I was surprised to learn that, on the login page, I can actually select different DEs, like Cinnamon, Plasma, Ubuntu, Unity, Wayland... that's really amazing! I have played around with Plasma and Cinnamon, and decided to stick with Cinnamon (after tweaking it with the dark theme, it looks awesome). So happy to have many choices though.

I wonder why people still feel the need to come up with more DEs instead of contributing to the plenty of existing ones...

> like Cinnamon, Plasma, Ubuntu, Unity, Wayland...

Wayland is not a DE though.

I don't know what Wayland is, but it is in the drop-down list.