If you run Ghidra on a high DPI screen, you will probably find the GUI to be scaled down so small to be almost of no use.
There is a setting that you can adjust to scale the Ghidra GUI:
in $GHIDRA_ROOT/support is a file named launch.properties.
If you installed Ghidra from the extra/ghidra package on Arch, this file will be located at /opt/ghidra/support/launch.properties.