Very, very little popular media is as self-critical as Garfield. Though the strip is constantly berated by the amateur critic for monotonous artwork, and eventlessness writing, these are part and parcel with the themes and worldview of Garfield. It is the running gag and major character trait of Jon Arbuckle to be boring. The meta-gag of this strip is that maddening tedium is a job hazard of documenting the life of a dull man and his lazy cat. It's practically the mission statement. Garfield's conspiratorial glare at the audience in panel two indicates this is about more than the cat being Jon's irritated foil. The joke boils down to "WHY does this comic strip exist?", and that is a dangerous question for any art to ask.
The man with nothing to say and no one to hear it is a special Everyman archetype, entirely unidealized, unromantic. He's not just a funny dork character, but everything boring about our lives. If we wonder why anyone would bother writing, drawing, let alone reading, a daily check-up on a character whose essence is to be dull, the answer is that no page in the newspaper will give you real life like the three panels devoted to Garfield. The rest of the news is dedicated to documenting the "remarkable", the noteworthy, the extraordinary. The rest of our entertainment diet for the day is spent escaping life or pinpointing those moments that give it meaning. Those times when everything makes sense, those moments we remember until we die: those are rare and fleeting. Jon Arbuckle's daily struggle is the great wash of our lives in between those moments. Garfield isn't boring: you are.