Target Display kind of sucked in that you needed a fully functional installation of MacOS running the entire time too. It’s nice that the feature was there of course, but I never found it pleasant to use.
The problem is the Cinema Display doesn’t look identical to the iMac. I like have monitor symmetry, but there was (maybe until the M1’s mini) a gulf in hardware between the iMacs and Minis. Especially the pros.
