If you're looking to restrict Chromebook use, turning off guest mode is a good starting point and there are a few other options too.

Using Chrome OS's Guest mode feature, attackers can view your Wi-Fi logs to get your location and track you. Here is how to disable guest mode.

You can disable Google Chrome's Incognito Mode and Microsoft Edge's InPrivate mode on your computer or phone. Here's how to do it.

Google’s latest Chrome addition allows users to make the browser open in Guest mode by default. You can read the instructions for turning on Chrome’s “Default to Guest mode” feature below.

Google announced today that a 'Default to Guest mode' feature is now available for Windows, Linux, and macOS power users of the Chrome web browser.