Google explains the reason here: https://chromium.googlesource.com/chromiumos/docs/+/1792b43fc9fd32b4e9e4aa03ad20a6c24f511d84/containers_and_vms.md#security ht

Google explains the reason here: https://chromium.googlesource.com/chromiumos/docs/+/1792b43fc9fd32b4e9e4aa03ad20a6c24f511d84/containers_and_vms.md#security https://chromium.googlesource.com/chromiumos/docs/+/1792b43f... tl;dr Isolating Linux and any arbitrary code running under Linux protects ChromeOS.