Unnesessary services which makes computer boot and stop slower.
https://www.freedesktop.org/wiki/Software/Plymouth/
Plymouth is an application that runs very early in the boot process (even before the root filesystem is mounted!) that provides a graphical boot animation while the boot process happens in the background.
1. Check if plymouth services are on
sudo service --status-all | grep plymouth
2. Disable services
systemctl stop plymouth-quit-wait.service
systemctl disable --now plymouth-quit-wait.service
systemctl mask plymouth-quit-wait.service
systemctl stop plymouth-read-write.service
systemctl disable --now plymouth-read-write.service
systemctl mask plymouth-read-write.service
systemctl stop plymouth-start.service
systemctl disable --now plymouth-start.service
systemctl mask plymouth-start.service
An alternate way is disable via sudo
sudo systemctl stop plymouth-quit-wait.service
sudo systemctl disable --now plymouth-quit-wait.service
sudo systemctl mask plymouth-quit-wait.service
sudo systemctl stop plymouth-read-write.service
sudo systemctl disable --now plymouth-read-write.service
sudo systemctl mask plymouth-read-write.service
sudo systemctl stop plymouth-start.service
sudo systemctl disable --now plymouth-start.service
sudo systemctl mask plymouth-start.service