There were Itanium workstations (https://www.openpa.net/systems/hp_i2000.html, https://www.openpa.net/systems/hp_zx2000.html), but of course these quickly crashed and burned with the rest of Itanium

Yeah, I had forgotten that by the Windows XP/Server 2003 era, the latter was definitely a server product, with XP targeting the workstation world.

That still seems weird to me. If I had to rely on a PC for high-end work in that period, I wanted the server SKU.