No one I know who was using those technologies at the time (including myself) was a designer nor used a Mac. Apple had 2-3% market share in the early 00s, and still below 5% in 2005. Virtually every computer user was using USB for one thing or another by then.
So a base of N+1. I was a designer in the late 90's/early 00's. I worked for a large, well known global agency. We had iMacs. I also had one at home and remember the "pain" of USB, though supported peripherals (Iomega ZIP disks spring to mind) came fast, mainly aimed at the largest userbase for Macs at the time - designers.
I happened to use a ZIP drive as well on the PC. There’s no relation to Macs here. Designers in the US tended to use Macs, yes, but this isn’t what drove USB adoption, and it would have happened in much the same way without them.
USB ZIP drive on a PC in 1999? Possibly with an added card. I called ZIP drives out specifically because I remember being surprised at how quick they were in comparison to SCSI attached ZIP drives. And how much less hassle they were.
I sort of agree with what you are saying, but don't underestimate the impact that the G3 had on the desktop computing landscape.
