OS/2 2.X was superior to Windows 3.0 but lacked the apps and marketing to compete with it. IBM Client Access/400 for DOS ate into the 640K layer and OS/2 used Extended RAM to keep more of the 640K for WIN-OS2 and DOS programs. Once Microsoft released Visual BASIC for 16-bit Windows, IBM had nothing for OS/2 mode like Visual BASIC. Borland had Delphi and Turbo C++ for Windows 3.0 but not for OS/2.
OS/2 started as Advanced DOS at Microsoft and IBM, by the way. An open-source project called OSFree (OS/3) wants to write OS/2 from scratch: https://osfree.org/
At my employer, I had to downgrade OS/2 2.X systems to MS-DOS 6.2 and Windows for Workgroups 3.11 before OS/2 Warp 3.0 and Windows 95 came out. Microsoft also had affordable license fees for DOS, Windows, and Office. We had to have everyone on the same OS for compatibility reasons and OS/2 lost out.
OS/2 started as Advanced DOS at Microsoft and IBM, by the way. An open-source project called OSFree (OS/3) wants to write OS/2 from scratch: https://osfree.org/
At my employer, I had to downgrade OS/2 2.X systems to MS-DOS 6.2 and Windows for Workgroups 3.11 before OS/2 Warp 3.0 and Windows 95 came out. Microsoft also had affordable license fees for DOS, Windows, and Office. We had to have everyone on the same OS for compatibility reasons and OS/2 lost out.
You can still buy the OEM version of OS/2 here: https://www.arcanoae.com/arcaos/