Everything is better than a hard shutdown right? I would at least try to wake up your PC with:
Maybe reactivate your system with crlt+alt+f3 for TTY (hope it works) and crlt+alt+f2 for back to desktop or try to shutdown from TTY with shutdown commands like:
shutdown -P now
There are other shutdown commands available too.
Btw. since how long you experience this shutdown problems?
Removing Plymouth with deleting this both commands:
quiet splash from Grub, this should atleast show you the steps what your system is doing before its shutdown and probably, where it stucks.
And after saving the Grub file, don’t forget this command:
sudo grub-mkconfig -o /boot/grub/grub.cfg
Here is the Tutorial, but that info that i gave you should already be enough: