Me: That's exactly my question, so I asked ChatGPT.

ChatGPT: If that actually happened, it would radically change the power balance between IBM, Microsoft, NeXT, and Apple within the personal computing landscape.

1. Microsoft - Microsoft's Windows will now face stiff competition vs NeXTSTEP OS. It will lose its monopoly in the OS industry. If IBM migrates to NeXTSTEP OS, Windows loses its dominance as the OS standard. This would have been a wake-up call to Bill Gates. Steve Jobs would have gotten his revenge
2. IBM - NeXTSTEP OS' GUI and object-oriented OS is clearly more advanced vs Microsoft Windows. The initial 'try' of IBM may result in full migration to NeXTSTEP OS, leaving Microsoft with diminishing buyers for its Windows
3. Compaq/Dell, et. al. - IBM's migration to NeXTSTEP OS is a green light for other computer manufacturers to follow suite. This breaks Microsoft's dominance in the market
4. NeXT - with NeXT hardware and NeXTSTEP OS licensed out, NeXT can dominate the market. NeXTSTEP OS runs on multiple hardware architecture (cross platform capability - NeXt, IBM, Compaq, Dell), positioning itself as a versatile and more sophisticated alternative to Windows or the MacOS. NeXTSTEP OS becomes a de facto standard in the same way Android became the de facto standard in smart phones
5. Apple - with Apple still being a closed system, the NeXTSTEP OS propagation (and all its clones) will further marginalize Apple

Overall, NeXTSTEP OS would have dominated the market, making NeXT the dominant industry standard. It could have been bigger than IBM, Apple and Microsoft.