You're conflating workstations with personal computers.
In the 90s systems like OS/2 and NeXT were defined as "workstations" to make a distinction between the old lineage of personal computing platforms (like Win 9x and Mac OS running on typically budget hardware) from high end systems running typically multi-user systems (often literally mainframe OSs).
Post-90s and the "workstation" definition went away when NeXT became OS X and NT replaced the DOS-bootloaded Windows lineage; and dedicated workstation hardware became cost ineffective due to improvements in consumer hardware -- not least of all x86 (and later AMD64).
In the 90s systems like OS/2 and NeXT were defined as "workstations" to make a distinction between the old lineage of personal computing platforms (like Win 9x and Mac OS running on typically budget hardware) from high end systems running typically multi-user systems (often literally mainframe OSs).
Post-90s and the "workstation" definition went away when NeXT became OS X and NT replaced the DOS-bootloaded Windows lineage; and dedicated workstation hardware became cost ineffective due to improvements in consumer hardware -- not least of all x86 (and later AMD64).
But in the 90s the distinction was real.
https://en.wikipedia.org/wiki/Workstation