The irony is that BeOS was designed specifically to take advantage of modern computer hardware of the day and cared nothing for binary compatibility with other OSes, and today Haiku is clinging to an ancient compiler and a dead x86 architecture... in the name of compatibility with BeOS apps, no less. BeOS itself moved from Hobbit to PowerPC to Intel x86 with little care for compatibility.
What made BeOS exciting 20 years ago was it promised to give users better multimedia support and responsiveness. Other OSes have caught up with the innovations and surpassed them. (Multithreading, multiprocessing, multitasking, journaling file systems, etc.) Some users liked the GUI and lauded it as a clean and a great interface. I hated the yellow tabs. Still, that's just personal preference -- Mac OS X has a clean and polished interface that suits that purpose today. In fact, the death knell of BeOS was when Apple declined to purchase BeOS and bought NeXTSTEP instead... because it was superior and led to today's OS X.
Point being that BeOS offered new, cutting edge features and better functionality on the same hardware than other OSes at the time. It seems that Haiku is the last of the BeOS clones and it's not progressing at a rate that will ever offer users significant benefits over modern OSes today.
What does Haiku have to offer? I mean - when it's finally released in a few decades or centuries at this rate and our ancestors get to enjoy it on their x86 or even AMD64 emulators?
There's a nice bit of fluff at : https://www.haiku-os.org/about , but that doesn't really answer the question. The key strength compared to Linux seems to be that a single team is developing and integrating everything with a common goal. Why couldn't that same team (or one as dedicated) simply fork a Linux distribution and all software it uses to customize and integrate towards the same common goal?
Seems a waste to re-invent the wheel creating new drivers and struggling to build on the Haiku platform for backwards compatibility without any clear, solid, user-recognizable benefit.
I get that it's interesting as a project and great practice for coders, and I truly wish Haiku well in its continued development... I just don't see the point if the development will never release outside of Beta with support for modern hardware. If Linux still struggles to get decent drivers, I can't imagine Haiku ever getting proper support.
Haiku seems like another stagnant AmigaOS, Syllable Desktop, or other relic. ReactOS at least has some benefit to Linux and potentially former Windows users by furthering WINE development even if it never makes it out of alpha (going on 17 years now btw.)