It looks to me that the general commercial drive is to make Linux a platform for "Apps", probably so that middlemen can own the distribution channels and siphon  money of both developers and end users. The wayland protocol would form part of that as a way of isolating "Apps" from each other rather than providing the well integrated computing platform that was/is one of the drivers behind X11.

bootlogd, if installed, kicks in after the devnodes are set up.

Iif you have another computer, you could set up a netconsole and then capture it there. Possibly with some clever hands-on, you could point that to a localhost console started (as early as possible) by initrd scripting. That would of course only capture from when that console starts.

Any bootloader  (or earlier) output before the kernel is started might require a video camera, possibly even a fast-recording one.

It might be possible to debootstrap if you add

--exclude=logrotate,cron,cron-common-daemon

to the command.

Ah yes, you also need to

mount -t efivarfs none /sys/firmware/efi/efivars

Note that the /dev/dri/* devnodes should be in group video and the same for /dev/fb0; group video with read+write access. They are made so by eudev, so the first guess would be that you are using some other hotplug handler which fails to do so.

The second part of that is that the user also needs to be in group video.

cryptsetup-initramfs is not a forked package, so you should report to bugs.debian.org rather.

Presumably some residue from incompletely removed packages, but there is something claiming to be systemd-udevd in the log. Check for /lib/systemd/systemd-udevd and /ur/lib/systemd/systemd-udevd and remove that, and restart.

The other udevd logs (apparently competing with the extraneous systemd-udevd) belong to the eudev package, which I would have thought you installed as replacement. If not, then you have to chase up which binary is involved and where it comes from. Something like this (as root) perhaps:

# find /bin /sbin /lib /usr -name '*udev*

Which permissions does it have/get and which permissions would you want?
Do you use eudev?

Afaict, assuming you have eudev installed, the mode for /dev/dri/renderD128 would be set b.m.o line 42 in /lib/udev/rules.d/50-udev-default.rules.

Answer about seatd and elogind would start with asking which "service managment" you are using; (apparently not sysvinit?)

About apt using ipv4 there's web results like this, suggesting by example:

sudo apt-get -o Acquire::ForceIPv4=true install pkg
sudo apt-get -o Acquire::ForceIPv4=true update
sudo apt-get -o Acquire::ForceIPv4=true upgrade
sudo apt-get -o Acquire::ForceIPv4=true dist-upgrade
sudo apt-get -o Acquire::ForceIPv4=true install ksh

Are you using excalibur?

Then the firmware-iwlwifi package installs the firmware to the wrong place; it installs into /usr/lib/firmware/intel whereas the kernel like always will want it in /lib/firmware/intel. If that's the case, please lodge a bug report to debian about it, as well as doing your own hands-on to make it work.

Apparently many debian packagers have decided to install stuff at different pathnames than before, which means that any script or program that has used full path is no longer working.

Likewise all existing documentation using the old pathnames is then outdated and wrong.

If you have the disk image you can mount that on som other system and run that update command there. Or even patch the initrd directly (unpack, patch, pack).