Yeah, ugly time for sure!
SGI was another casualty, though it was PCs running Linux that did it.
A lot of digital effects were done on IRIX. And like Amiga groups, the studios experienced serious price pressure and in a rare move, developed open tools together, then shared them to bootstrap onto Linux.
Amiga computers were not always replaced with Windows.
Microsoft mooched the shit out of SGI tech, while largely doing as little as possible to help the SGI NT computers succeed.
The big players were on IRIX. Win NT ports of stuff like Maya brought in cheap fast workstations. But, the tooling was crap and a lot of that Win NT share ended up on Linux, not back on IRIX.
Back when this all happened, it was shell scripts and lots of custom programs.