Google has ended support for older Androids.
You can still use the Samsung you purchased three years ago. These are old devices that run Android 2.3.7 and lower. This is Android Gingerbread. It was released in December 2010. However, it's worth noting there are billions more Android devices. There are also a lot of people still using older phones.
Google (via Reddit/Engadget) has the news. It also provided details about the changes in a support file.
Google will not allow sign-in to Android devices running Android 2.3.7 or less starting September 27, 2021. This is part of our ongoing efforts for user safety. The document states that you might get password or username errors if you try to sign in on your device after September 27.
Many users will lose their phone due to the importance of Google apps and Google services for Android devices. You can still save your phone by updating to an older Android version (3.0+) or higher.
In reality, no one should use a device that is this old. Security issues, bugs, and other problems build up over time. You also increase the chance of your device being infected by malware.