https://www.techradar.com/news/oneplus-6-always-on-display-mode

The OnePlus 6 offers a lot of features for your money, but it doesn't have wireless charging, IP water-resistance, or an always-on-display mode – at least not anymore.

It turns out a briefly present always-on display mode was buried in the settings of the new phone, as a Redditor discovered, but it was removed in a day one update.