Personally I think it’s far more important that Audacity is the best open source audio editor, and one of the few that is available for Linux. However, this is an open source app, so you should be asking yourself “what are you going to do about it?” (Hint: repeatedly complaining that “others” have not made it look prettier is not constructive and only serves to annoy.)
Background:
Back in 2007, I was annoyed by the poor quality of the pink noise generator in Audacity, so I learned enough C++ to be able to improve it, and submitted a patch to the Audacity team. The patch was accepted and Audacity now has an “instrumentation grade” pink noise generator.
Also:
Audacity can look very nice with a custom theme, for example: Arc-DarK theme (Arc-Dark with DarK icons) - #30 by mischamajskij