I've spent about 10 minutes clicking through looking for anything even mildly technical. The first link you sent me, "plenty of docs", is a 2 page PDF product brief & 5 web pages describing some features at a high level. There's a ton of docs... for game developers, application developers, &c. Talking up features & capabilities. But for making drivers? For describing how to use the hardware? There's some links to embedded development / DDK development sites for arm, but none of them are open accecss. ARM wont help.

The Debian drivers you cite are the Panfrost Lima drivers, which are the reverse engineering works everyone else did in the dark with no help from ARM, until very very recently.

I am not conflating anything. ARM has provided no documentation no support to help folks make drivers. I stand by my original post entirely, and disagree deeply. ARM's gpu chip design is stamped out into countless chips, verbatim or close to verbatim. Even if individual chip makers did want to support their chips, I suspect it is in fact ARM who would block them from releasing open source drivers, from documenting the chips they make: ARM's desire has been to protect it's IP, and to help the various embedded support partners that do know how to work with their chips and their IP in a secure fashion. ARM has been a bad player in the Linux world, has worked against allowing Linux support. The problem is absolutely ARM, not those vendors.