"Several years"?

Try "a decade and a half".

AT&T itself ported UNIX™ to the Intel 8086 in 1978:

https://www.nokia.com/bell-labs/about/dennis-m-ritchie/other...

The 8086 was the first ever microprocessor to run Unix – before 68000 or anything.

The first release of MS, later SCO, Xenix was 1981.

https://www.abortretry.fail/p/the-history-of-xenix

It was later ported to the 8086 in 1983 and 80286 by 1985.

https://landley.net/history/mirror/unix/scohistory.html

So Unix was running some 4 years before IBM launched the PC and Xenix was on the market by 2 years after launch.

That was a full 8 years before Linus got Linux 0.01 out in 1991.

UNIX is a 1970s OS; x86 PC Unix was a commercial 1980s product; Linux is a 1990s thing.

I worked in EDA while the transition happened. We and our customers had been big buyers of Sun and/or HP workstations. The switch happened several years after Linux was released. When x86 performance started to look competitive, there was a lot of interest in switching to NT, and very little interest in paying for SCO Linux etc. It wasn't until RedHat came out with an enterprisey amount of support that companies started to switch en masse.

And what about *BSD?