Haiku uses some important 3rdparty programs/libs like ntfs3g / gcc / Qt / etc.
Some works really well, others not really and most of the time the Haiku specific patches are not upstreamed.
Maybe Haiku should contact those projects and offer money to get somebody who knows the programs/libs, have commit right upstream and can help get the Haiku port in shape / reviews and upstreams the patches.
For the most part of the patches I do for haikuports I try (where it’s possible) to upstream the patches, maybe it’s not possible every where, but others could do it too (I know other patches have been up streamed, so it’s possible) 
Qemu displays warning when configuring that Haiku target is not maintained and will be removed if maintainer will be not found. Qemu is important software that helps a lot with kernel and drivers development.
What would it take to maintain the Haiku port for Qemu?
I never did maintainer job so I don’t know. Very few changes are needed to make latest Qemu version functional on Haiku.
At least -fPIE flag should be removed to avoid Qemu 6.0.0 crash on start, see #5859.
Personally I would be a bit annoyed to see the money donated to Haiku be used to fund Qt, which is somewhat of a direct competitor.
For gcc, our main problem until recently was that upstreaming our changes to gcc required assigning copyright to the FSF, which would require contacting all the involved people to get their agreement. This restriction was recently removed from gcc.
I think the upstreaming work is usually not so hard to do, and in most cases (although not always), other projects are happy to accept our patches and supportive. I think the main problem is ensuring long term support, making sure new releases still work, for example. I don’t know if that’s something we can pay for