When comparing Chromium OS vs Kali Linux, the Slant community recommends Kali Linux for most people. In the question“What are the best Linux distributions for desktops?” Kali Linux is ranked 45th while Chromium OS is ranked 56th.
Ranked in these QuestionsQuestion Ranking
Pro Minimalistic interface
Chromium's system UI uses as little screen space as possible by combining apps and standard web pages into a minimal tab strip: While existing operating systems have web tabs and native applications in two separate strips, Chromium OS combines these, giving access to everything from one strip. The tab is the equivalent of a desktop application's title bar; the frame containing the tabs is a simple mechanism for managing sets of those applications and pages.
Because Chromium OS is designed for users who spend most of their computer time on the Web, it is intended for use in computers with little local storage and fast boot-up times.
Pro Safe and requires little to no maintenant
Since you only have the browser, you cannot install applications (outside Chrome Apps which are decently protected by their limited API and the Chrome Web Store). This means no harmful virus, and also nearly no way you can screw your system. Everything will just work.
Pro Standard pentest tool set
Pro Better than ParrotOS, BackBox for hacking purpose
Contains too many tools for hacking. Those tools are not already included in BackBox or ParrotOS.
Pro Live session distro used for forensics
Possibly harms your privacy.
Con No auto-upgrade (unlike Chrome OS)
Chrome OS auto-upgrade the system, but Chromium OS does not. It's possible that they're thinking about adding that feature from the design doc.
Con Not intended to be a daily driver
This distro was written for pen testing and security work. It is not meant to be a day-to-day OS (unless that's your job).
Con Very old packages
E.G. Firefox's current version is 61 but Kali linux consists of its 52th version. Though kernel is not that old.