Plymouth is a graphics interface which makes the bootup and shutdown menu look more elegant instead of a terminal like look. Many distros use this such as Ubuntu and Mint as examples.
The reason I would like to see this added all of Manjaro's editions is mainly because of the painful encryption menu Manjaro currently uses. When one installs Manjaro using the LUKS encryption which will encrypt the entire Manjaro installation and require a password on booting up Manjaro, it does not have a graphical interface and these are the issues I have with it...
Since there is no GUI, I cannot tell if I am typing and how many characters I have entered. There is no password field circle characters
If you enter your password wrong, it will go into some GRUB Rescue thing and the only way for me to try again is for me to turn off my computer by pressing the power button, turning it back on and trying again. On other distros such as Ubuntu if you enter the wrong password which can happen like when you login into any account, you may press the wrong key you will get rejected but you will be able to try again.
A nicer polished distro. Manjaro is a user friendly version of Arch. I know it is more than that but it allows non-techie people to use an Arch based distro since it works out of the box, easy installation, many desktop environments to choose from and for those who want to use Arch without the hassle of setting it all up manually Manjaro makes it easy. But I find the system encryption feature not user friendly and not elegant as Manjaro.
My first daily driver distro was Linux Mint and I thought this was the best distro for me. Then I switched to Manjaro since I wanted to try Pamac and get the latest version of software and now I can say that Manjaro beats Mint due to the AUR alone. This is my only request for Manjaro to do. Please add Plymouth and make Manjaro startup, shutdown and system encryption menu more user friendly!