Not necessarily. If you go to bugs.kde.org, you can just describe the bug in your own words: what you do to trigger the bug, the expected result, what really happens, etc.
Of course it is best if the bug is reproducible, i.e. that you discovered that every time you do x, y and z, a crash happens, for example. Like that, devs can confirm that it is indeed a bug of the software and not something that happens only due to some special configuration or hardware problem.
It may help getting backtraces in DrKonqui which are needed if there are underlying bugs that are not visual, like very slow startup, crashes, out of memory bugs (memory leaks) etc.
Also running journalctl -f --priority err on startup can help. Normally there should be no error messages, although this never happens.
Some distros (Fedora at least) have debuginfod integration,meaning that gdb will automatically download debuginfo files. The downside is that it will take a while for download to finish (for the first time at least) since it gets symbols for all linked and loaded libraries recursively, and it will take a few gigabytes in ~/.cache.