You asked why Nouveau is used by default?
Because it usually just works with any Nvidia hardware.
That is what you want to happen the very first time you try to boot Bionicpup64 8.0.
If Bionicpup64 8.0 was 4GB in size. It could come with every possible driver and firmware, already installed.
Not going to get every possible thing in a 300 to 400 MB OS.
I have some old Nvidia hardware that the latest Nvidia driver will not support.I asked to have "nvidia" instead of "nouveau" driver to have better video performances. If it doesnt work with some old hardware (which is rare nowadays),
The last driver to support it was the Nvidia 173 series ones.
I can not even compile that driver in Bionicpup64 8.0
The software the diver package wants to use for compiling is too old or no longer used.
Even if it would compile.
Bionicpup64 8.0 is using to new of everything else, to get it to run.
Puppy Linux tries to support as much older hardware as possible.
Generic graphics drivers OTB do that.