I understand that Microsoft originally intended to bring dynamic wallpapers to Windows 11 with version 23H2, but that ended up not happening for some reason.

There's a special variant of the Windows 11 "Bloom" wallpaper that's only available on Microsoft's exclusive 50th anniversary ...

TIP: Download Windows 11 wallpapers in exciting colors for your PC. On the top right corner, there is a toggle to switch on and off the Dark Theme based User Interface.