In those days, I was using SGI machines to build web sites for folks .. the Indy was very popular for this purpose. One day I was given a DEC Alpha machine to evaluate and see if it was a worthwhile addition to our inventory.
It came with NT, so there was some friction to just adding it to our services. These days were very frustrating - Microsoft was hell-bent on killing Unix, and later Linux also - and there was a lot of back and forth in our engineering team whether we wanted to invest in this hassle.
We didn't. I had that machine under my desk doing basically nothing for a year, before I sent it back.
If there had been a bit more insight into the nature of things, and if it had been running a Unix variant, we would have given it a better chance.
So then it was even more frustrating when SGI did a deal with the devil in later years, and tried to get its customers switch to NT, also. That killed SGI, in my opinion.
Looking back now, it's kind of incredible the resistance to Unix in those days, and how it was all going to be replaced with some "New Technology". Linux won. SGI didn't. And DEC was an early victim they should have learned from, in my opinion.
From Microsoft’s POV they soundly beat Unix in the 1990s because they were primarily focused on the GUI workstation market.
In 1991 the market for high-end desktop software like engineering, video editing and 3D modeling tools was dominated by Unix and classic Mac. In 1999 all of those applications were on Windows NT.
Vendors like Autodesk and Avid were building for Windows first. New graphics acceleration hardware targeted PC add-on cards rather than being exclusive to a workstation vendor (SGI tried this approach with their NT box and it flopped).
In retrospect it was just commercial Unix that had lost the game, but it wasn’t obvious at the time that Linux could reclaim this market. And Mac OS X was considered by many a doomed project (after all Apple had been promising a new OS for the entire ‘90s, nobody knew how deeply the NeXT acquisition would transform the company).