Depending on your use case, what style you're looking for, and what device you're using, different options might work better than others for getting the best 4K wallpapers. For desktop computers ...

Former Microsoft designer shares unreleased Windows 11 wallpapers, including Live designs. Unreleased wallpapers highlighted key design changes like a centered Start menu in Windows 11. Download ...

The latter is equipped with a new version of the standard Windows 11 Bloom wallpaper. There is also a dark variant, which is not included with the Windows 365 Link. Here they are in high resolution.