well the thing is it's open source. that is no guarantee for safety but with some popularity it's as close as it gets. many people would probably love to write a paper about the Cybersecurity of deepin - especially if there are juicy issues.
i had this DE for a while and liked it. for example it has a simple right click menu for per-application-scaling as far as i remember. and it's pretty.
Deepin is a desktop environment (windows is the desktop environment for the “windows” os) deepin runs on Linux. There are other desktop environments like gnome and kde. Which are open source. Deepin is a Chinese gov de