SUMMARY
***
I mark this as a regression. Previously in KDE 6 the panel was starting instantaneously after sddm login. You typed password and the panel was "immediately" there. It was like the star of the show- to show people how fast KDE was. Now we have to wait (cogwheel plus after desktop load) before it starts.

STEPS TO REPRODUCE:
0. Login to KDE.
1. See how long it takes the panel to appear. Compared to previous versions of KDE 6, after sddm login we now we have splash-screen with cogwheel (wait...) and then empty desktop, wait...and then wait... and then panel pops-up. It may not be too obvious on a fast computer (...), but its definitely slower then previous versions of KDE 6.
2. See your own logs

OBSERVED RESULT:
Slow KDE panel startup.

EXPECTED RESULT:
1. Change back to the previous sequence of KDE panel startup. The changes to KDE startup sequence slow down the panel appearance/loading after login.

Maybe some changes to the network/dbus/"calling the mother-ship" sequence startup have created this regression. Compare it to the previous versions of KDE 6, before the change. PiTA, I know, but I didn't make up this bug and I didn't change the startup sequence (for whatever reason). It affects me.

MY SETTINGS:
Settings: all default, except "classic task manager" and Layout: Desktop; not a single icon on the panel either! (I use krunner). FYI: I read Arch wiki and removed network ping/check at startup! So don't ask me this question.

KDE Plasma Version: 6.1.4
KDE Frameworks Version: 6.5.0
Qt Version: 6.7.2
Graphics Platform: X11