The Galaxy S21, Galaxy S21+ and Galaxy S21 Ultra are set to feature an exciting upgrade in the form of improved biometrics. Apparently, the devices will have a UD fingerprint scanner that is two times faster than the one in the Galaxy S20 series, and with a much larger surface area to boot. Additionally, the FCC has confirmed that there will be Qualcomm Snapdragon 888 versions of the Galaxy S21 series, too.
https://www.notebookcheck.net/Samsung-Galaxy-S21-series-tipped-for-new-UD-fingerprint-scanner-as-FCC-confirms-Qualcomm-Snapdragon-888-versions.508721.0.html
Either Samsung have really advanced the miniaturization of their phones, or that's one giant thumb.