PC vendors would have invested in alternative OS builds and support, obviating that issue. Had this been done years ago, we'd have a much more competitive OS market, rather than what we have now.
The vendors had no interest in alternatives.
What they wanted was a place in the lucrative market that had evolved around the IBM PC and PC clone.
In the eight bit era there were many competing operating systems in the home market. If you needed an office machine, CP/M was your first and most likely only choice.
The IBM PC was designed to make the transition to the 16 bit world as painless as possible for the both users and developers. Third party software support for the MSDOS and IBM PC was strong from Day 1 and evolved rapidly over the next two years.
--- and by decades end had eclipsed everything in sight.
The Mac doesn't make its appearance until 1984 --- with barely enough resources available to support the Mac GUI.