That's inaccurate as I have OS/2 on 2.88 MB Disks from IBM.OS/2 was only ever delivered on 1.44MB disks (and CDs); the post-4.0 convenience packs were delivered via bootable CD images. There were definitely some X-series IBM machines delivered with 2.88-capable floppy drives, though.
Games were generally found on 1.2MB disks. KQ V comes to mind. Also MS-DOS 6.xx and MAybe 5.xx were also available on 1.2MB FDD (although more 3.5" units were shipped). Heck I even have MS-DOS 6.22 on 360KB disks from MS (had to fill out a form and send them out.In terms of disks I've acquired over the years, I've yet to get a 1.2MB HD 5.25" floppy. Even during my years of servicing computers, I've yet to come across anyone using them. Same goes for 2.88MB, but the drives were never widespread outside of IBM and NeXT shipping them OEM on their machines.