BeOS could have been OS X :)
If Apple had bought Be instead of NeXT, they would've have gotten Steve Jobs, who (arguably) saved Apple from bankrupcy, plus i{Mac,Pod,Phone}
At the time (1995-96?) BeOS was a (cool) tech demo, but wasn't a viable product. It had no developers and no apps. NeXT was mature. BeOS also didn't have critical things like - the ability to print, colour management, multi-user support, etc.. Apple could've added these to BeOS, but...
[0] https://9to5mac.com/2011/11/11/gassee-thank-god-apple-chose-...