In the current version of Chrome 105, a hidden feature was discovered: the ability to protect browsing tabs in incognito mode with biometrics. If you minimize the app or lock your phone, you will need to use your fingerprint or passcode to access open pages.
The feature was in development for quite a long time: it was first noticed in 2021 in the beta of Chrome 94. However, at that time, the developers only found the corresponding checkbox in the settings, it was impossible to enable it. It is surprising that it has not yet been launched, because on iOS it was already possible to block incognito tabs using Face ID.
To enable this blocking, make sure the app is updated to Chrome version 105 and go to chrome://flags/#incognito-reauthentication-for-android. Flip the switch to the active position, reload the app, and you’ll see an option in your privacy and security settings to block incognito tabs when you sign out of Chrome.
Perhaps this feature will be made more accessible in future updates, but for now it can only be activated this way.