Does anything useful happen during the KDE Plasma5 splash screen load delay? It seems to just waste time
Solution 1:
It depends on your definition of "useful". It's there so that you don't have to see the different parts of Plasma (e.g. panel, desktop, icons, etc) loading one at a time if your system is slow. There is no problem with turning it off if your system is fast enough that everything appears instantly, or if you don't care that things appear one-at-a-time.
Source: am a KDE developer. :)