For me it only works with any degree of longevity,if humorous lyric is used in a song,but the whole song isn't necessarily comedy. Some Leonard Cohen song lyrics make me laugh/smile.
Getting away with being relentlessly miserable in the context of a song is much easier than 3 minutes of 'now you must laugh'. Plus you can never tell the same joke to the same people twice,or they'll need to harm you physically and with great authority.
I know tinam doesn't wish to be regarded as comedy/novelty ( I read your post Tina,before the edit
) to be fair to her,she'd probably not like to be pigeonholed as anything at all,but I like how she uses her offbeat humour to provoke a reaction and still preserve the integrity of the song. Further listens don't blow the joke or devalue the piece.
Anyway,that's just me,thank god we're all different,it'd be a dull world otherwise.