For those with very old Android devices (some used for specific functions): Sign-in on Android devices running Android 2.3.7 or lower will not be allowed starting September 27, - Android Community (google.com)
As part of our ongoing efforts to keep our users safe, Google will no longer allow sign-in on Android devices that run Android 2.3.7 or lower starting September 27, 2021. If you sign into your device after September 27, you may get username or password errors when you try to use Google products and services like Gmail, YouTube, and Maps.