[…]Drewry and Liu focused on four key features for the Chromebook that have been available ever since the first iteration in 2010:
sandboxing,
verified boots,
power washing and
quick updates.
These provided security features that made it much harder for malware to pass through, while providing a quick fix-it button if it ever did. “That’s the fundamental difference between how Chrome OS works and how any other computer at the time worked,” Liu said.[…]

https://www.cnet.com/uk/news/how-google-chromebooks-became-the-go-to-laptop-for-security-experts/