Just ran into this exact problem this morning which was incredibly frustrating. Performed a routine system update, and I'm pretty sure I had a kernel panic (all input was non responsive, couldn't even switch to a tty) in the middle of pacman's upgrade phase.

While I was able to chroot into my install and reinstall the kernel, half of my system's packages were left in an inconsistent state so I still couldn't properly boot - and so I just nuked my root subvolume and reinstalled Arch (I suspect I could've somehow got the packages reinstalled if I wrangled for a while with pacman but it was just easier to reinstall at this point).

Atomic distros like Bazzite are designed to prevent that exact situation I ran into, unfortunately I just haven't had enough time or energy to try to make my own custom image that has what I need in it (got kind of close with NixOS but that had its own issues), otherwise I'd probably be running that.