I've noticed that all versions of qt6-webengine only weight a handful of KiBs, and completely lack all libraries:
$this->bbcode_second_pass_code('', '
$ pacman -Qi qt6-webengine
Name : qt6-webengine
Version : 6.3.0-2
Description : Provides support for web applications using the Chromium browser project
Architecture : aarch64
URL : https://www.qt.io
Licenses : GPL3 LGPL3 FDL custom
Groups : qt6
Provides : None
Depends On : qt6-webchannel qt6-positioning libxcomposite libxrandr libxkbfile libevent snappy nss libxslt minizip ffmpeg re2 libvpx libxtst ttf-font pciutils
Optional Deps : pipewire: WebRTC desktop sharing under Wayland [installed]
Required By : qt6-webview
Optional For : pyside6
Conflicts With : None
Replaces : None
Installed Size : 7.78 KiB
Packager : Arch Linux ARM Build System <builder+seattle@archlinuxarm.org>
Build Date : Sun 17 Apr 2022 07:50:47 AM CEST
Install Date : Tue 10 May 2022 05:14:27 PM CEST
Install Reason : Explicitly installed
Install Script : No
Validated By : Signature
$ pacman -Ql qt6-webengine
qt6-webengine /usr/
qt6-webengine /usr/lib/
qt6-webengine /usr/lib/cmake/
qt6-webengine /usr/lib/cmake/Qt6/
qt6-webengine /usr/lib/cmake/Qt6/FindGPerf.cmake
qt6-webengine /usr/lib/cmake/Qt6/FindGn.cmake
qt6-webengine /usr/lib/cmake/Qt6/FindNinja.cmake
qt6-webengine /usr/lib/cmake/Qt6/FindNodejs.cmake
qt6-webengine /usr/lib/cmake/Qt6/FindPkgConfigHost.cmake
qt6-webengine /usr/lib/cmake/Qt6/FindSnappy.cmake
qt6-webengine /usr/share/
qt6-webengine /usr/share/licenses/
qt6-webengine /usr/share/licenses/qt6-webengine/
qt6-webengine /usr/share/licenses/qt6-webengine/LICENSE.chromium
')
The Qt5 version doesn't suffer from this issue, so it's strictly a Qt 6 problem.