[colechristensen]

But the RPi is broadcom and arguably the best supported. Obviously this is special.

From experience I agree with you, the chipmakers suck because they utterly fail to be open source when they're one of the groups that needs it the most. It is to the extent that I would advocate for laws in the theme of right-to-repair to force chip vendors to provide source for necessary code to use their products to consumers. (in this case open source in the narrowest definition, they can keep their copyrights but would be required to distribute source to end users in a form and with a license that makes them usable)

If the question is "are any of the SBCs worth the trouble?" and the default answer is no unless I have a really good reason and want to dedicate the time to building the janky software stack (I don't), or they're from a small list of vendors I'd trust won't be a mess (RPi, nvidia, beagle, ... that's it off the top of my head)

[joezydeco]

Were the kernel and BSP improvements and ongoing support for RPi produced by Broadcom, or by the user community?

[colechristensen]

There is some sort of close relationship between Broadcom and the raspberry pi foundation which is not entirely clear, they are a bit more than just customers although companies use the “partnership” label to mean just about anything.

[joezydeco]

The relationship is very clear: Upton was a Broadcom FAE that started the RPi Foundation. The secondary story was that he found a use for an orphaned SoC and embarked on an 'educational' quest to make small computers for classrooms.

The real question is if Broadcom is devoting internal software resources to improving the ecosystem, or if it's coming from the devoted users. I don't track commits on kernel.org enough to know what's what.