I've been watching Haiku OS development (OpenBeOS previously) for as long as I can remember, and I will put below some of what I have concluded, and this gonna be a little bit lengthy. (and you are free to correct me)
This development has been going on forever (20 years?), but at least we have now an almost stable BeOS clone, a pleasing to look at desktop, basic file management, still running in a virtual machine, good to run some built in demos and clones of incredibly out-dated FPS games.
I hate to see this great effort turning to another Amiga nostalgia-good-for-nothing-OS, or something like FreeBSD world of Linux compatibility layers to patch some important OS areas like sound or 3D acceleration because developers possibly went lazy and stop researching something unique and started copying the readily working good old neighbor open-source OS (and I don't mean Haiku devs are lazy, this is just a warning, you guys rock!), the thing is FreeBSD never got any real benefit from doing that, they haven't taken any share of users or support from the Linux world despite being compatible, this approach does not work.
What I believe works is to start researching new methods and stop looking at Linux code and not try hard to let DRM compile or work efficiently! It's just a huge waste of time! And you'll end up with the same bloat of code that Linux currently has.
Haiku OS inherited the good Kits approach with a minimal micro kernel, and I think the best way to to extend and modernize those Kits adding more Kits on the way if needed.
Again please correct me if I'm wrong, I'm not trying to troll, just describe what I feel around all this situation.
I want this to succeed!