Randomly figured out what was causing the initramfs problem. The bootloader that’s built into the phone can only boot Android boot.img. Contained within it is a kernel and a ramdisk
I never paid much attention to the ramdisk, since I’ve only modified the kernel, but turns out that the ramdisk is the initramfs. When running mkbootimg (this is to create a boot.img that my phone can boot), you specify where the ramdisk is stored in memory