> I can't imagine why anyone would choose to run System Vr4

With X, using an Amiga 3000/4000 as a daily driver is possible. I did use an IBM PowerPC 43P as a daily driver under AIX 3.1 for a long while (until I gave up on having ssh working on it).

The 43P was, however, paired to a humongous Intergraph CRT that I can't move across a national border because of the amount of rare earths used to make it, and was a very ample desktop for the 2010s. Until the advent of 4K monitors, I didn't have anything beating that - on a VGA connection. The Amiga is far more limited than that.

In terms of vintage Unix desktops, it's hard to beat Acorn's RISC/iX with its IXI desktop. I believe Atari Unix also had something similarly cool.