There are so many ways they could help. For GPU, they could support freedreno (both the kernel and Mesa parts) instead of KGSL and the closed source Adreno libraries.

A great start would be to make the user space Adreno GLES libraries talk to the freedreno DRM backend. So one could use the QC proprietary GLES libs with a mainline kernel without rebuilding with KGSL.

There's a similar story here for every subsystem driver, where they insist on a brittle proprietary solutions (one branch for every chip!) that can't be upstreamed.