Galaxy S21 series was promised up to 4 years of updates, which means that One UI 7 will be the last major update.

After four years, monthly security updates have ended on the Galaxy S21 series as Samsung will now provide quarterly updates only.

The problem is that right now, you can only trade in specific Samsung devices. That includes phones from the Galaxy S20, S21, S22 and S23 ... computer peripherals, mobile apps, and much more ...