The only big UNIX where I actually did install GNU stuff was on Solaris 2.6 via the GNU packages repository, because I was requested to do so.
All our HP-UX and Aix boxes used the vendor tooling (including the C compilers).
Fortunately that didn't work when you needed 3D graphics hardware. But I guess you worked in a 'server' company, not a graphics (3D or engineering) one?
> All our HP-UX and Aix boxes used the vendor tooling (including the C compilers).
Of course, GCC was only needed for most of the later (early 2000s) OSS like Mozilla that didn't work with the native compilers because of missing GNU extensions. That's one thing I don't miss - the prices of compilers. SGI took more than 10,000 € for their MipsPro C, C++ and Fortran compilers but without 'advanced' optimization options like auto parallelization and their 'IDE' tools, Developer Workshop. That reminded my of Totalview (a debugger from ???): now Perforce bought them https://totalview.io/
Or SGI Onyx, for another example.
In fact the whole cloud streaming hype is basically a bunch of people rediscovering graphics programming with timesharing on UNIX.
Actually one way to mix both, while controlling what people were allowed to do on their workstations was to boot via tftp and have $HOME mapped noexec over NFS.
A solution used in some labs at the university campus.