Earlier quoted context omitted.
They've now relaxed their (stupid) policy so at least the default ISO includes non-free drivers. When it comes to an already installed system, enabling the non-free repos and installing linux-firmware (or more specific firmware-* package for your hardware) should fix it.
If the default ISO already included non-free drivers, why would you have to separately enable the non-free repos to get firmware? My Debian 12 install didn't come with proprietary Nvidia drivers, nor did it ask me if I wanted them during installation. I had to enable the non-free-firmware repo to get them.
Here is the relevant part from the release notes:
> In most cases firmware is non-free according to the criteria used by the Debian GNU/Linux project and thus cannot be included in the main distribution. If the device driver itself is included in the distribution and if Debian GNU/Linux legally can distribute the firmware, it will often be available as a separate package from the non-free-firmware section of the archive (prior to Debian GNU/Linux 12.0: from the non-free section).
> However, this does not mean that such hardware cannot be used during installation. Starting with Debian GNU/Linux 12.0, following the 2022 General Resolution about non-free firmware, official installation images can include non-free firmware packages. By default, debian-installer will detect required firmware (based on kernel logs and modalias information), and install the relevant packages if they are found on an installation medium (e.g. on the netinst). The package manager gets automatically configured with the matching components so that those packages get security updates. This usually means that the non-free-firmware component gets enabled, in addition to main.
https://www.debian.org/releases/bookworm/amd64/ch02s02.en.ht...