New Microsoft Edge browser will allow users to stream Netflix videos at both 1080p HD and 4K UHD resolutions. Chromium-based browsers such as Google Chrome, Opera, and Brave can stream up to 720p using the WideVine DRM technology. Microsoft has added the PlayReady DRM to their upcoming Microsoft Edge Browser. Users on Reddit have been trying the new Edge browser to stream 4K videos without any lag. The new browser is expected to go into public preview soon, so we should get more feedback about this feature.
Source: https://www.bleepingcomputer.com/news/microsoft/chromium-microsoft-edge-can-play-4k-netflix-video-unlike-chrome/