Galaxy S21 smartphones offer custom backgrounds during video calls via Cisco Webex, Google Duo, Microsoft Teams, and Zoom.
This is currently incorrect as the S21s, or at least most of them, do not support custom backgrounds during video calls Microsoft Teams. As for Zoom, the quote is misleading because Zoom has being providing custom background support since at least the Samsung Galaxy S9 and Android 10.
Can one add a virtual background with Cisco Webex and Google Duo with a Samsung Galaxy S21?
If it depends on the S21 version, then my main interest is the Samsung Galaxy S21 Ultra (US version).