AFAIK, Hybris isn't just for the GPU and is used to port various binary Android drivers to ubuntu touch, sailfish, tizen, luneos etc as can be seen from the following chart:
Yes, it can be used any time there is a need for blob that depends on bionic and there is no open replacement. May be for touchscreen driver in this case? That's why it's such a mess with Android only hardware.
No idea why Tizen needs it though. Samsung can afford writing normal drivers for all their hardware.
AFAIK, Hybris isn't just for the GPU and is used to port various binary Android drivers to ubuntu touch, sailfish, tizen, luneos etc as can be seen from the following chart:
https://wiki.merproject.org/wiki/Adaptations/libhybris