I remember I've reduced that dependency a bit already. Not sure if it's Fedora 30 or Fedora 31.
The reason why lxqt-themes-fedora is written as a dependency to lxqt-session is to make it the default theme. De-coupling the kde stuff from LXQt themes while keeping the old appearance is not an easy task for me. I'll possibly look into this in January (due to being too busy recently).

Yesterday I rebuild lxqt-session removing lxqt-themes-fedora from required (koji).
Works ok.

Yes, technically it works. But I remember the theme (logo on the application menu etc) is not the current Fedora specific theme as that is defined in lxqt-themes-fedora.

Created attachment 1637262 [details]
lxqt-themes-fedora requirements

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After some careful consideration, I think I will not drop lxqt-themes-fedora as dependency of lxqt-session. Judging from comment 4, I think the overall aim you want to achieve is to reduce the unessential KDE packages. And I agree that makes a lot of sense. I'm changing the component to lxqt-themes and will focuse on getting rid of the unessential KDE stuff.

Right now the status is, the lxqt-themes-fedora can only depends on the following

$ sudo dnf install lxqt-themes-fedora
Last metadata expiration check: 0:09:49 ago on Mon 25 May 2020 09:18:51 PM +08.
Dependencies resolved.
==============================================================================================================================================================================================
 Package                                           Architecture                  Version                                Repository                                                       Size
==============================================================================================================================================================================================
Installing:
 lxqt-themes-fedora                                noarch                        0.15.0-1.fc31                          copr:copr.fedorainfracloud.org:zsun:lxqt                        1.5 M
Installing dependencies:
 breeze-cursor-theme                               noarch                        5.17.5-1.fc31                          updates                                                         328 k
 breeze-icon-theme                                 noarch                        5.68.0-1.fc31                          updates                                                         4.9 M
 desktop-backgrounds-compat                        noarch                        31.0.0-1.fc31                          fedora                                                          8.5 k
 f31-backgrounds-base                              noarch                        31.0.4-1.fc31                          updates                                                          36 M
 fedora-logos                                      x86_64                        30.0.2-3.fc31                          fedora                                                          4.8 M
 lxqt-themes                                       noarch                        0.15.0-1.fc31                          copr:copr.fedorainfracloud.org:zsun:lxqt                        3.1 M

Transaction Summary
==============================================================================================================================================================================================
Install  7 Packages

Total download size: 50 M
Installed size: 78 M

And I see the rest of the KF5 part comes as a dependency of ark. As lxqt-archiver is now released, I'll replace ark with lxqt-archiver so that the kf5 stuff will be mostly get rid of.

This bug appears to have been reported against 'rawhide' during the Fedora 33 development cycle.
Changing version to 33.

Built in a side tag f34-build-side-34835

FEDORA-2020-8c75c8b822 has been submitted as an update to Fedora 34. https://bodhi.fedoraproject.org/updates/FEDORA-2020-8c75c8b822

FEDORA-2020-8c75c8b822 has been pushed to the Fedora 34 stable repository.
If problem still persists, please make note of it in this bug report.