Using F12 on www.bing.com, I can the webpage is using 4K version of the wallpaper.
However, new tab page only uses 1080P version of wallpaper even if I am using a 4K display. I can sometimes see pixels in the wallpaper with this resolution and it certainly helps to use 4K wallpaper for 4K displays.
@ZZYSonny Thanks for reaching out! Tagging in @Alyxe from our Bing Insider's team to see if she can provide some insights.
Fawkes (they/them)Program Manager & Community Manager - Microsoft Edge