@abcdw not totally surprising that the one that the majority of users use today and has full-time teams on it is the most convenient and visually pleasant.

Bugzilla and Debbugs both come from a time when (a) email was the main interface, (b) where you're looking at bugs at a scale most FOSS projects won't see. Launchpad is another that tried to solve 'bugs at scale' - it's a hard problem.

I've never used it but some people love Fossil for the integration of code+bugs.