In precicse, when the splash screen is enabled, a boot failure that lands you at the initramfs emergency shell is not shown. To reproduce, just edit the boot line at the grub prompt and change the root UUID. If you remove the splash argument, you get the initramfs rescue shell like you should, if you do not, then you are just stuck at the blank plymouth splash screen forever.
In precicse, when the splash screen is enabled, a boot failure that lands you at the initramfs emergency shell is not shown. To reproduce, just edit the boot line at the grub prompt and change the root UUID. If you remove the splash argument, you get the initramfs rescue shell like you should, if you do not, then you are just stuck at the blank plymouth splash screen forever.