System: Kubuntu 20.04 LTS

Long story short,
I did the following:

apt remove --purge kdevelop

find /usr/ -type f -name "*kdev*.so*"

rm -rf /usr/lib/x86_64-linux-gnu/libblockdev.so.2.0.0

apt remove --purge kwrite

find /usr/ -type f -name "*kwrite*.so*"

rm -rf /usr/lib/x86_64-linux-gnu/qt5/plugins/kf5/kded/kwrited.so

apt autoremove

apt install kwrite

apt install kdevelop

and now some things don't work anymore; some programs take 5 minutes to start and some do not start at all.

These files are not installed and I think that is the problem.

/usr/lib/x86_64-linux-gnu/qt5/plugins/kf5/kded/kwrited.so

/usr/lib/x86_64-linux-gnu/libblockdev.so.2.0.0

One possible solution is to reinstall the KDE Plasma desktop, but I don't want to lose my settings (colors, icons, animations, features...), I've been working on this for 1 month and I'm still not done.

How can I solve this without losing my desktop settings?

If you want to know why I did this, here is the full version:
I was missing a function in Kate and KDevelop, the plus sign for opening folders in the sidebar. Kubuntu uses version 19... of Kate, but there is already version 21... available and in the 21 version the plus sign is present. There is no repo for Kate only the Ubuntu reopsetory, so I had to download the appimage. After I started the Kate app image, I had to wait about 30 seconds when clicking on a folder until it opened.
I thought this is because Kate V.19... is installed and uninstalled Kate V.19 with apt remove --purge kate. But nothing has changed. Then I remembered that Kdevelop is also installed and it also works with Kate, so I uninstalled KDevelop too (apt remove --purge kdevelop). But it didn't help either, so I cleaned the system with apt autoremove and searched for Kate files and removed them. after esystem reboot it started. The KDE Plasma Desktop takes 5 minutes to start. Dolphin File Exlorer takes 5 minutes to start and can't access other partitions and drives. GNOME Disk Utility does not start at all, and so on.