On my arch systems I see a much larger initramfs for the fallback boot and it is similar, but smaller in artix.
Why are the sizes so different. I assume that systemd is the reason for the bigger sizes in Arch. And I imagine that autodetect is off for the fallback which makes it larger (because of additional modules).
I no longer seem to have /etc/mkinitcpio.conf.d/linux.preset.
Do I need such a large fallback initramfs?
#Arch
-rw-r--r-- 1 root root 7.8M Jun 1 01:46 intel-ucode.img
-rw-r--r-- 1 root root 13M Jul 13 08:10 vmlinuz-linux
-rw------- 1 root root 15M Jul 13 08:10 initramfs-linux.img
drwxr-xr-x 4 root root 4.0K Jul 13 08:10 .
-rw------- 1 root root 122M Jul 13 08:10 initramfs-linux-fallback.img
#Artix
-rw-r--r-- 1 root root 7.8M Jun 3 16:07 intel-ucode.img
-rw-r--r-- 1 root root 13M Jun 29 19:31 vmlinuz-linux
-rw-r--r-- 1 root root 80K Jul 12 02:09 amd-ucode.img
-rw------- 1 root root 6.9M Jul 19 15:41 initramfs-linux.img
-rw------- 1 root root 47M Jul 19 15:41 initramfs-linux-fallback.img
I'd check compression section in arch's mkinitcpio.conf.
I personally never had need in fallback images and did disable the creation of it, But your experience may differ. 122M is not such big deal for modern systems and by "modern" I mean the last dozen years or so.
I compared /etc/mkinitcpio.conf in Artix and Arch and they only differ in the HOOKS.
I used lsinitcpio to list the contents and for me the main difference in the Arch vs Artix initramfs-linux,img is that Arch needs i915 firmware (9Mb) and has more modules in the image.